AfterSalesTraining R312 Supplementary Restraint Systems Published by AfterSalesTraining  MG Rover Group All rights reserved. No part of this publication may be reproduced, stored as a retrieval system or transmitted in any form; electronic, mechanical, recording or other means, without prior written permission from MG Rover Group

Supplementary Restraint Systems Preface MG Rover Group are constantly seeking ways to improve the specification and design of its vehicles and alterations take place continually. Whilst every effort is made to produce up-to-date literature, this training workbook should not be regarded as an infallible guide to current specification, nor does it constitute an offer for the fitment of any particular system or component. All rights reserved. no part of this Workbook may be reproduced without prior permission of – MG Rover Group Ltd PO Box 41 Lickey Road Longbridge Birmingham B31 2TB England This Training Workbook is designed to support AfterSalesTraining courses and is issued as part of the training programme. It may be used to compliment other literature available but the Repair Operations Manual should always be consulted prior to servicing or repair work. © MG ROVER GROUP LIMITED – January 2002 Course Code R312 Supplementary Restraint Systems

index Index ………………………………….….4 …………………………….5 ………………………………6 …………………………………….7 …………………………………….8 ………………………………….9 …………………………………………………10 . …………………………………12 …………………………………….13 ……………………………………….14 …………………………………15 … ..……………………………..16 ………………………………………17 ………………………..18 ………………………19 ………… ..……………25 …………………………………….26 ………………………… ………………………….31 …………………………..32 … .. ……………………………….33 …… ………………………………………34 … ……………………………….………36 …… ………………………………………38 …… ………………………………………..39 …… ………………………………………..40 ……………………………………………… ….41 ………………………………………… …..42 ……………… …………………………..44 ……… ……….47 ………………… ………………..49 ……………….……… ……………….50 ………….……… ………………..55 ………………………….……… ………………..56   Index Primary safety …………………………… Supplementary safety ………………… Airbag safety issues ………………… Warning lamps ………………………… Warning labels ………………………… SRS components ……………………… DCU …………………………………… Rolamite sensors . ……………………… Rotary coupling …………………………… Drivers airbag …………………………… Passengers airbag ………………… Side impact sensors … ..…………………… Thorax airbags …………………………… Inflatable tubular structures ……………… Front seat belt pre-tensioners …………… Rear seat belt pre-tensioners ………… ..… System operation ………………………… Mini ………………………… ……………… Rover 100 & 200/400 XW …………… Rover 200 96 MY … .. ………………… Rover 400 …… ……………………… Rover 600 … …………………… Rover 800 …… ………………… Rover 25 …… ……………… Rover 45 …… ……………………… MGF …………………………… Rover 75 …………………… Diagnostics ……………… ……… Component replacement strategies ……… Harness strategies ………………… ……… Harness repair ……………….……… …… Tools & equipment ………….……… …… Safety ………………………….……… ……   index

Primary Safety Seatbelts (Main Primary Safety) Anti-Submarining Seats Vehicle Design Exterior /Interior Primary Restraint The primary restraint equipment fitted to the vehicle consists of the seatbelt anti sub-marine panels in the seat and a occupant safety zone built into the body construction. They are designed to hold the occupant in their seat under all crash conditions, be it frontal, rear, side or roll over. It is important to stress that seatbelts should always be worn, regardless of whether other safety features are fitted to the vehicle.

Supplementary Safety Airbags Seat Belt Pre-tensioners Airbags The airbag system is referred to as a Supplementary Restraint System (SRS) because it is in addition to the primary restraint system. The sole function of the airbags fitted to current vehicles is to prevent the occupant’ s head and upper torso from hitting the steering wheel, or the fascia in the case of the front seat passenger or any other intruding objects likely to cause grievous harm. Seatbelt pre-tensioners When a 3 point seatbelt is worn, there is always a certain amount of slack to allow the passenger to move freely. If bulky clothing is being worn, the amount of slack can be considerable. During a frontal collision, an occupant is thrown forward until the seatbelt restrains them. From a safety point of view it is desirable to restrain the occupant as far away from the steering wheel or fascia as possible. Seatbelt pre-tensioners are used to further improve the safety of the vehicle. As the name suggests, in the event of an accident, the seatbelt pre-tensioner tightens the seatbelt before the passenger is thrown forward, hence limiting their forward movement.

Airbag Safety Issues Passenger Airbags and Small People Possible Facial and Upper Torso Injuries Possible Burns and Fume Inhalation Vehicle Accident Rescue Operation

SRS Warning Lamps Warning Lamps The SRS warning light is located either in the instrument pack or on the driver’ s airbag module depending on the system fitted to the vehicle. The purpose of the warning light is to inform the driver of the condition of the supplementary restrain system. The light is controlled by the Diagnostic and Control Unit (DCU). When the ignition is switched on, power is supplied to the DCU which performs a self check routine to ensure that the system is functioning correctly. During the self check routine, the DCU switches the warning light on to inform the driver that the system check is being carried out and also to confirm that the bulb is working. Provided that the system is operating correctly, the DCU will extinguish the warning light when the self check is complete. The self check procedure typically takes 3 to 6 seconds. If the DCU identifies a system fault, either during the self check routine or during its continuous monitoring process with the ignition switched on, the warning light will be illuminated. If the warning light fails to illuminate during the self check routine, fails to extinguish after the self check routine or illuminates while driving, a fault has occurred in the system. On some models, the warning light can be used to retrieve a fault code stored in the DCU memory by giving a flash code.

SRS Warning Stickers Warning Labels To assist the technician in identifying a vehicle that is fitted with an airbag, an identification label is fitted to the vehicle, either on the locking platform, sun visor or side window glazing. The warning label refers the reader to the handbook and highlights the dangers of using rear facing child seats in the front passenger seat of the vehicle.

SRS Components Power Supply Fuse Diagnostic and Control Unit (DCU) Airbag/s Rotary Coupler Crash Sensor (Early Vehicles) SRS Wiring Harness Seat Belt Pre-tensioners Side Impact Sensors SRS Wiring Harness The SRS wiring harness connects the various components of the system together. The harness is often separate from the body or fascia harness and usually identified by either yellow trunking or black and yellow striped trunking. The harness is divided into two circuits. One half provides the power to the DCU from the vehicle battery and operates at 12 volts. The second half is referred to as the “firing circuit” and carries the firing charge from the DCU capacitors to the pyrotechnic devices. The firing circuit typically operates at 25 volts. It is important that the SRS harness is not tampered with as an accidental open or short circuit will lead to a system fault or accidental system deployment. Vehicle accessories, such as mobile telephones, must not be wired into the SRS harness. The harness can be repaired using the specialist repair process detailed later in this workbook. Extra care should be taken when working on the SRS harness to ensure the wiring is not trapped or at risk of chaffing. Check also that the latching mechanisms on the various electrical connections are fully mated. When an airbag or pyrotechnic seatbelt pre-tensioner is deployed, a large amount of heat is produced by the gas generator. The high temperatures can adversely affect the SRS wiring harness near the gas generator connection, even though no damage may be visible externally. To guard against possible system faults, the relevant SRS circuit or harness must be renewed after airbag or pyrotechnic pre-tensioner deployment in vehicle.

SRS DCU Safing and crash sensors Single point sensing Multi-point sensing System control and self check Back up power circuit Contains sensors used to detect severe collision to warrant SRS deployment Diagnostic Control Unit The Diagnostic and Control Unit (DCU) is the heart of the SRS system. The DCU performs 3 main functions. Firstly, it monitors and processes signals it receives from the release sensors. Secondly, if the DCU detects a signal which indicates that a severe frontal collision is occurring, it sends a fire signal to the airbag modules and seatbelt pre-tensioners, when fitted. The DCU must be capable of differentiating between a real crash situation and general vehicle abuse such as striking a pavement or driving on rough roads. Great care is taken in the design of the vehicle and Supplementary Restraint System to ensure deployment does not occur unless required. Thirdly, the DCU carries out a system test each time the ignition is switched on, including a resistive measurement of each airbag firing circuit. Subsequently, with the ignition switched on, the system continuously monitors itself and associated circuits to ensure that the system is functioning correctly. If a fault is found, the DCU will not allow the SRS to deploy and indicates the fault to the driver via the SRS warning light. A fault code related to the identified problem is stored in the DCU memory. The fault code can be retrieved by a vehicle technician via T4, TestBook or flash codes to aid the diagnosis and rectification of the fault. Because different vehicle models behave differently during collisions, the DCU is tuned to match the characteristics of one specific vehicle range. As a result, although some vehicle DCU’ s appear, externally, to be the same, they are dedicated to one vehicle range only and must not be fitted to a different vehicle. The DCU contains capacitors which store the charge required to fire the airbag/s and pyrotechnic seat-belt pre-tensioners, if fitted. The capacitors ensure that the SRS system will be deployed in the event of a severe collision, even if the battery is destroyed during the accident. Because the DCU retains a stored charge, safety precautions must be followed to allow the backup power circuit to discharge before commencing work on SRS components. If the safety precautions are ignored, there is a slight possibility of accidental system deployment which could result in personal injury. All airbag systems contain at least two release sensors which are wired in series. The ‘crash sensor’ is programmed or tuned to sense when a collision is severe enough to warrant airbag deployment. The ‘ safing sensor’ is programmed to trigger at a lower deceleration (typically 1.5G) than the crash sensor and confirms to the DCU that the vehicle is decelerating rapidly. For the airbag to fire, both release sensors must be activated. Having two release sensors ensures that a simple system fault does not result in accidental airbag deployment and hence provides a factor of safety The DCU can sense crash events to the vehicle monitored through 360° via internal accelerometers and remotely located side impact crash sensors. The acceleration data is electronically processed by an internal microprocessor controller to determine the severity of the crash condition. The DCU is able to use the input data to distinguish between a severe crash situation and a minor impact or rough road conditions and so prevent spurious deployment. .

SRS DCU Safing and crash sensors Single point sensing The DCU can sense crash events to the vehicle monitored through 360° via internal accelerometers and remotely located side impact crash sensors – where fitted. The acceleration data is electronically processed by an internal microprocessor controller to determine the severity of the crash condition. The DCU is able to use the input data to distinguish between a severe crash situation and a minor impact or rough road conditions and so prevent spurious deployment. An electromechanical safing sensor is incorporated into the DCU which is a normally open switch, but closes at a preset deceleration limit. Electronic switches for each of the airbag squibs and seat belt pre-tensioners are activated if the severity of the crash condition exceeds a pre-determined trigger value. CAUTION: It is important that the DCU is correctly mounted and is fitted in the designated location and orientation to ensure correct operation. Main Sensor The main sensor is a deceleration device which is contained in the DCU. The sensor consists of a spring and weight system which is attached to strain gauges in a Wheatstone bridge circuit. The ’balance’ nodes of the bridge circuit is connected to an integrated circuit that can instantly detect a change in the monitored resistance. In the event of a collision, the spring and weight move causing a corresponding change in the resistance of the related strain gauge. If the change in strain gauge resistance is greater than a preset value, it corresponds to a crash condition of sufficient severity to warrant SRS component deployment. In this case, the processor provides a signal to initiate airbag module and/or seat belt pre-tensioner deployment. Deployment will only be carried out if a confirmation signal that a crash condition is occurring is received by the SRS DCU. Crash condition confirmation is achieved by the simultaneous actuation of the safing sensor. Safing Sensor This sensor is also contained within the DCU and is included in the DCU internal circuitry to prevent unintentional detonation of SRS components. The safing sensor is connected in series with the main sensor and operates at comparatively lower rates of deceleration. When the safing sensor closes in conjunction with the main sensor exceeding its trigger value, electronic switches are activated, allowing electrical current to be supplied to the driver and passenger airbag squibs and seat belt pre-tensioners. The operation of the side (thorax) airbag modules (where applicable) are controlled by electronic switching in response to the threshold value for the side impact crash sensors being exceeded, and arming of the safing sensor. The safing sensor also acts as an arming sensor for the seat belt pre-tensioners. Safing and crash sensors Single point sensing Multi-point sensing System control and self check Back up power circuit Contains sensors used to detect severe collision to warrant SRS deployment

Early Type Crash Sensors (Rolamite) The Rover 800 system utilised two electro mechanical sensors located in the engine bay at the front of the vehicle. These sensors, plus a safing sensor in the DCU, complete the circuit that activates the airbags. The crash sensors are of the Rolamite type and are located in the engine bay of the vehicle, one on each side. The basic Rolamite mechanism consists of a thin, flexible band wrapped around a roller. The band is fixed at both ends with enough tension to cause the roller to contact the guide surface and bias it against a stop. In the event of a severe frontal collision, the forces placed on the roller overcome the band force, causing the roller to travel beyond the electrical contact inside the sensor, thereby completing the circuit. The wiring to the sensor is as a normally open switch in parallel with a resistor. The resistor allows the DCU to continually monitor the wiring and sensor connections. The fixings to these two components (sensor and DCU) provide earthing for the system. Always ensure specified fixings are used and tightened to the correct torque.

Rotary Coupling Rotary Coupler The rotary coupler is part of the SRS wiring harness and provides a reliable electrical link between the rotating steering wheel and stationary steering column. It is located behind the steering wheel and connects the SRS harness from the steering column to the airbag module. A continuous wire ribbon is wound inside the rotary coupler, rather like a watch spring, which allows the centre of the coupler to rotate with the steering wheel while the outer remains fixed to the steering column. The rotary coupler may also connect horn, cruise control and radio remote switches. The following points should be noted when dealing with rotary couplers: The SRS rotary coupler is unique to airbag vehicles and is different to cruise control couplers. Special care should be taken when removing the steering wheel or rotary coupler. The relevant workshop manual contains specific instructions. Road wheels should be centralised before removing rotary coupler. DO NOT dismantle, lubricate, tamper or attempt to repair the rotary coupler. In the case of abnormality, the rotary coupler should be renewed.

Drivers Airbag 4 5 Steering Wheel Cover With Break Lines Airbag 3 Ignition Charge 5 Initiator (Squib) Fuel Tablets 7 Heat Exchanger And Filter 3 Drivers Airbag The driver's airbag is attached to the steering wheel by two captive bolts. Electrical connection to the SRS DCU is provided via the rotary coupler. When a deployment signal has been received at the airbag module, the squib initiates combustion of the igniter charge. The igniter charge burns rapidly and produces sufficient heat to cause the sodium azide gas generating pellets to burn and so produce a large quantity of nitrogen gas which is routed to the folded nylon airbag. The force of the inflating airbag causes the steering wheel polyurethane centre pad to split at deliberately weakened break points and expands to form a protective cushion between the driver and the steering wheel / windscreen. The fully inflated airbag has a capacity of 45 litres in most cases but can vary from model to model. Once the airbag is fully inflated, vents in the airbag prevent further pressure build-up, so that progressive deceleration is provided as the driver contacts the cushion and so prevents injury due to sudden impact forces. The design of the airbag is 'tuned' to match the crush characteristics of the vehicle as well as the steering wheel and collapsing steering column behaviour. 6 2 7 1

Passengers Airbag 1.Electrical Connector 2.Nitrocellulose Chamber (Containing Squib) 3.Mixing Chamber 4.Gas Release Port 5.Pressurised Nitrogen/argon Gas Chamber 6.Filter 7.Folded Nylon Bag 8.Housing 9.Paper Cover The passenger front airbag module is usually located above the glove box within the fascia, directly in front of the passenger seat. The airbag module is securely mounted to the fascia support with its own dedicated mounting bracket. The module contains a gas generator and igniter unit, which incorporates the nitrocellulose igniter charge and pressurised gas chambers surrounded by a filter screen. The filter prevents solid combustion by-products from entering the airbag during deployment. The front passenger airbag module connects to the fascia harness, via a yellow multiplug connector which plugs into the back of the airbag module. When an activation signal is received by the passenger airbag squib, the activated igniter charge produces heat causing a small quantity of nitrocellulose to ignite and generate nitrogen gas. The pressure of the expanding gas from the nitrocellulose chamber punctures the port of a nitrogen/argon gas chamber. The pressurised gas which is released expands to rapidly fill the nylon bag. Vents are located in the back of the airbag to allow expulsion of the gas as the occupant strikes it to provide a safe controlled deceleration. Front passenger airbag capacity can vary from 80 litres to 120 litres. WARNING: Vehicles fitted with a passenger airbag should not be driven for 24 hours after replacing the windscreen.

Side Impact Sensor Green Rover 45 Black Rover 75 Side Impact Sensor The side impact crash sensors are located beneath the carpet under the front seats, on the front face of the seat cross members on Rover 75 and on Rover 45 the sensors are fitted to the inner sills just forward of the B/C posts. Each sensor consists of an electronic accelerometer, microprocessor and serial link circuit. The sensor uses the accelerometer to determine the severity of a side impact, and if the impact is great enough to warrant supplementary restraint operation, the sensor communicates the need for deployment to the central DCU via a single line serial link. The side impact crash sensors must be fitted in the correct orientation, and there must be no gap between the sensor and the cross member mounting position. Ensure the fixing screws are tightened to the correct torque. Be careful when refitting front seats not to damage sensors or sensor harness. Green Rover 45 Black Rover 75

Thorax Bag Side Airbags (Thorax ) The driver and passenger side (thorax) airbags are mounted to the squab seat frame and are designed to protect the ribs and upper internal organs during side impacts. The modules are handed (i.e. a right hand module must be fitted to a RH seat and a left hand module must be fitted to a LH seat). The side airbags are activated by a control signal from the SRS DCU in the event of a side impact or a front angled impact of sufficient severity to cause both front and side airbag deployment. The side (thorax) airbag module is comprised of a moulded plastic case which houses a folded nylon fabric bag, the gas generating capsules and an igniter squib. The rear of the side airbag module features two studs which are used for mounting the module to the seat frame and are secured in position by two nyloc nuts. The back of the module also has moulded plastic location lugs, which are offset to ensure that only the correctly handed module is fitted to the relevant seat. WARNING: If the location lugs on the back of the module casing are damaged or missing, the module should not be used. Dispose of using the controlled procedures detailed in this manual. The side airbag modules have a flying lead which terminates in a yellow 2–pin connector. The connector connects to the DCU via the main harness and is located beneath the seat cushion. CAUTION: Do not try to remove the connector at the module end, it is a permanent connection. When a severe side impact is detected by the DCU, electronic switches are closed causing a small electrical current to be supplied to the igniter squib in the airbag on the side of the vehicle affected by the impact. The activated igniter charge produces heat causing the 3g of nitrocellulose to ignite and generate nitrogen gas. The pressure of the expanding gas from the nitrocellulose chamber punctures the port of the nitrogen/argon gas chamber. The gas released from the nitrogen/argon chamber is then mixed with the gas from the nitrocellulose chamber in the central mixing chamber. The resulting nitrogen gas escapes from holes in the mixing chamber to rapidly fill the nylon bag. The force of the inflating bag, forces the module casing to split open and deploy the airbag through the seat seam at the piping line. The module is mounted at the outboard side bolster seam of the seat squab, and the expanding airbag initiates a seam thread failure in a designed and controlled manner. Once free of the module housing and seat cover, the nylon bag inflates to its full extent, pushing the seat occupant away from the side of the vehicle suffering the impact. When the bag is fully inflated, vents in the airbag prevent further pressure build-up and when the gas generation is exhausted, the airbag begins to deflate. The side airbag has a capacity of 12 litres.

Side Head Impact Protection Inflatable Tubular Structure Inflatable Tubular Structure (ITS) The Inflatable Tubular Structure (ITS) airbags are designed to protect the front seat occupant's heads from directly contacting the vehicle body side trim and from suffering impacts from intrusive objects in the event of a crash. The system also reduces neck injuries by limiting the movement of the head during the crash condition. The two ITS airbag modules are handed for LH or RH side fitment but are otherwise identical. The airbag is located behind the interior trim above the front doors. The igniter / gas generators are fixed to the body below the front fascia. The airbag itself is tethered to the body by two securing straps and bolts, one at the lower end of the 'A' post, the other above the rear window aperture. In between the two tether points, the airbag is held in place with plastic clips which are designed to break apart as the airbag inflates. The airbag is attached to the outlet port of the gas generator module using a crimped metal securing clip. When an activation signal is received by the gas generator, the activated igniter charge produces heat causing a small quantity of nitrocellulose to ignite and generate nitrogen gas. The pressure of the expanding gas from the nitrocellulose chamber punctures the port of a pressurised gas chamber. The gas which is released flows from the generator into the outer manifold and up through a Kevlar hose into the airbag cushion. The airbag rapidly expands to the point where the clips securing the airbag are forced apart and the headlining at the side of the impact is pushed away. The airbag then positions itself ready to protect the head of the occupant. The airbag cushion utilises a special weaving technology to shorten the cushion upon deployment and so ensure the cushion is tensioned for accurate positioning. The capacity of the inflatable tubular structure (ITS) airbag is approximately 12 litres when fully inflated. The A-post trim is tethered to the body using clips and straps so that it remains attached to the vehicle body during airbag inflation. The B-post upper trim is secured to the B-post by a special plastic fixing pin. After deployment, the ITS airbag deflates at a slower rate than for the front and side (thorax) airbags, this is to provide additional head protection in the event of a secondary impact.

Front Seat Belt Pre-tensioner (Buckle Type) Seat Belt Pre Tensioners During a frontal collision, the front seat belt pre-tensioners tighten the front seat belts to ensure the occupants are securely held in their seats. A pre-tensioner is integrated into the seat belt buckle anchorage of each front seat belt. The two pre-tensioners are handed, but otherwise identical. Each pre-tensioner has a tube containing propellant and a piston. The piston is attached to a steel cable, the opposite end of which is attached to the seat belt buckle. An igniter (squib) in the base of the tube provides an ignition source when triggered by a fire signal from the SRS DCU. On receipt of a fire signal from the SRS DCU, the igniter heats the propellant. The rapidly burning propellant produces nitrogen gas that rapidly expands to drive the piston along the tube, pulling the cable and drawing the buckle towards the buckle assembly fixing point on the seat. This increases the tension in the seat belt and prevents the occupant from moving too far forward during the crash condition. Tension is increased in both the lap and diagonal belts at the same time, the tension in the lap belt helping to prevent the occupant from sliding under the lap belt. Rover 200 Rover 25 Rover 75 MGF

Pre-tensioner Outer Casing Wiring Initiator Propellant Retaining Plate Gas Choke Piston & Cable Seal Seal Housing Clutch Operation Whether the pyrotechnic seatbelt pre-tensioner tightens the belt by shortening the belt webbing or retracting the buckle, the mechanism for producing the tightening effect is similar. A pyrotechnic device is located in a piston, which is retained in a tube. A cable attaches the piston to the seatbelt mechanism. When a fire signal is applied to the pyrotechnic initiator, the propellant burns rapidly, creating a large quantity of high pressure gas. The gas forces the piston and cable along the tube.

Rover 400/45 Front Pre Tensioners Operation The internal sensor consists of a series of springs, levers and a mass. When the unit is subjected to decelerative force, the mass presses against the release lever (via the sub release lever on RH units). The release lever is maintained in position by a spring which applies a specific load to the lever and resists the force applied by the mass. The release lever, in turn, holds the firing pin against a spring load. When the deceleration forces are sufficiently high due to a collision, the force of the mass pressing against the release lever overcomes the retaining spring force, moving the lever and releasing the firing pin. The firing pin spring forces the firing pin into the percussion cap of the gas generator. The percussion cap produces heat which initiates burning of the fuel in the pyrotechnic device. As the fuel burns, a large quantity of nitrogen gas is generated. The gas is directed through a port into a chamber and acts on a rotor. As the gas pressure increases, the rotor is forced to turn. The rotor is connected to the seatbelt reel and as the rotor turns, it winds the seatbelt back onto the reel. A ratchet prevents the rotor turning in the reverse direction when the gas pressure subsides. When the rotor reaches the extent of its travel, excess gas is ejected to atmosphere through an exhaust port. 4. As Rotor Turns, Webbing Is Wound Onto Reel 5. Rotor Reaches Limit of Travel, Gas Is Exhausted to Atmosphere 1. Pre-tensioner Prior to Firing 2. Gas Generator Produces Nitrogen 3. Gas Pressure Forces Rotor to Turn 1.Firing pin 2. Release lever 3. Sub-lever 4. Mass 5. Slide bar 6. Latch spring 7. Cover

Rover 400/45 Front Pre Tensioners Each of the pre-tensioner units is fitted with an igniter squib. When the igniter squib is provided with enough energy (crash signal), a chemical reaction is initiated which activates the main gas propellant, which in turn acts on an internal metal strip in the inertia reel, turning it back to tighten the slack in the seat belt webbing by up to 180 mm. The unit contains an internal clutch, when ignition takes place, the clutch pins are sheared off and the clutch engages to turn the inertia reel back by up to 180 mm. WARNING: Once the seat belt pre-tensioner has been operated, it cannot be reset. The seat belts will still function temporarily in the same way as normal seat belts, but the gas generant will be exhausted and the clutch pins sheared off. The unit must be replaced. The operation of the seat belt pre-tensioners is designed to compliment air bag operation in that the increased tension in the seat belt prevents the occupant from moving too far forward into the deploying airbag during the crash condition. Load limiters are fitted to the front seat belt webbing reels. These will limit the amount of load from the belt acting on the occupant in the event of a collision. Load limiters are fitted only to seat belt reels where an airbag is fitted for the seat occupant. The load is reduced via a torsion bar inside the webbing unit. When a collision event occurs, the inertia reel prevents the release of any more of the belt and the pre-tensioners take up any excess slack in the seat belt. The inertia from the accident forces the occupant forward into the belt, which is designed to elongate under loading. The amount of load transferred to the occupant by the seat belt can still be excessive as a result of severe deceleration of the vehicle. In this type of event, if the load reaches approximately 3.8 kN, the load limiter torsion bar in the reel housing twists. This twisting allows the release of a further small portion of the seat belt reel in a controlled manner and eases the load acting upon the occupant of the vehicle. 4. As Rotor Turns, Webbing Is Wound Onto Reel 5. Rotor Reaches Limit of Travel, Gas Is Exhausted to Atmosphere 1. Pre-tensioner Prior to Firing 2. Gas Generator Produces Nitrogen 3. Gas Pressure Forces Rotor to Turn

Rover 400 97.5 my Safety Switch 2. Seatbelt Webbing Rover 400 97.5 MY The unit is self contained and located at the base of the ‘ B’ post, behind the trim panel. There are no external sensors or electrical connections. Although the seatbelt pre-tensioner is a stand alone unit, it contains a pyrotechnic gas generator which is triggered by an internal sensor. After deployment, the unit is very hot and should be left for at least 30 minutes before handling. The unit is shock sensitive, care must be taken when working in the vicinity of the pre-tensioner. To avoid the possibility of accidental deployment, a safety switch is located on the unit . Before removing the unit from the car and while the unit is out of the car, ensure the switch is in the ‘ safe’ position. Do not attempt to dismantle or repair the pre-tensioner unit, it contains no serviceable parts and there is a risk of serious personal injury. Once the pre-tensioner has operated, it cannot be reset, it must be renewed. Do not allow fluid to contact the pre-tensioner unit. Do not fit a unit which shows signs of being misused or dropped. The pre-tensioners are handed, do not attempt to fit a right hand pre-tensioner to the left hand side of the vehicle. Safety Switch 2. Seatbelt Webbing

Rover 400 97.5 my 1. Depress Stopper Lever To set the pre tensioner into a safe mode for handling: - 1. Depress stopper lever 2. Turn lever and protector pin 90° anti-clockwise 3. Lift protector pin Fold protector pin flat against bracket and ensure clip is engaged 1. Depress Stopper Lever 2. Turn Lever and Protector Pin 90° Anti-clockwise 3. Lift Protector Pin 4. Fold Protector Pin Flat Against Bracket and Ensure Clip Is Engaged B. Safe Position

Rover 75 Rear Pre Tensioner During a frontal collision, the rear seat belt pre-tensioners are tightened to ensure the occupants are securely held in their seats. The pre-tensioner units are located underneath the rear parcel shelf trim and are integral with the seat belt inertia reel assemblies. The seat belt pre-tensioners are activated by a control signal from the SRS DCU in the event of a frontal collision. The three pre-tensioner inertia reels are identical both in terms of their orientation and operation; however, there is a difference in the web length between the centre and outer assemblies. Each of the pre-tensioner units is fitted with an igniter and a propellant generator which acts on a rotor which is attached to the seat belt inertia reel. When a severe frontal impact is detected by the SRS DCU, electronic switches are closed causing a small electrical current to be applied to the igniter squib. The igniter activates a nitro-cellulose charge which produces a Nitrogen and CO 2 gas. The gas pressure forces a piston up the cylinder. The piston draws a rack and pinion mechanism fitted with a roller clutch. The piston draws the rack which rotates a gear wheel mechanism to pull back the seat belt inertia reel and hold the occupant securely in the seat. When the rotor reaches the extent of its travel, excess propellant is ejected to atmosphere via a port in the end of the propellant tube. The reel is pre-tensioned up to a distance of 180 mm. WARNING: Once the pre-tensioner has been operated, it cannot be reset. The gear wheel locking pin will have been broken and the gas generant will be exhausted. The unit must be replaced. 1.Gas generator 2.Rack 3.Outer gear 4.Inner gear 5.Hub 6.Roller 7.Spool 8.Seat belt

System Operation System Operation The following illustrations show the approximate timings involved during a frontal collision when the vehicle is travelling at about 20 mph (32 kph) into a solid wall. The normal seating position of the driver using a three point seat belt configuration prior to impact is shown. Normal Driving Position - Driver Wearing A Three Point Seat Belt

System Operation 15 Milliseconds (0.015 Sec) After Frontal Collision About 15 milliseconds (0.015 seconds) after impact the vehicle is strongly decelerated. The SRS DCU detects a crash pulse severe enough to trigger airbag deployment. The airbag module squib is fired by the DCU and ignites the fuel in the gas generator. The driver is still in an upright position 15 Milliseconds (0.015 Sec) After Frontal Collision DCU Detected Severe Frontal Collision Safing Sensor Confirmed Rapid Deceleration DCU Sent Firing Voltage To Pyrotechnic Devices,Driver Still In Upright Position

System Operation 30 Milliseconds (0.030sec) After Impact After approximately 30 milliseconds the airbag unfolds. The material of the airbag travels at up to 200 mph (320 kph) during inflation. The driver is moved slightly forward and part of the vehicles crash zone will have been deformed 30 Milliseconds (0.030sec) After Impact Airbag Inflating Very Rapidly (200-300 Mph) Driver Being Thrown Forward Against Seatbelt Webbing

System Operation 40 Milliseconds (0.040sec) After Impact 40 milliseconds after impact the airbag will be fully inflated. The seat belt retaining inertia reel is locked, the seat belt absorbing the initial impact energy. As the driver hits the fully inflated airbag, it deflates through vents to provide progressive deceleration for the occupant 40 Milliseconds (0.040sec) After Impact Airbag Fully Inflated Drivers Head Strikes Airbag, Airbag Vents Through Holes / Porous Material.Venting Provides Cushioning To The Drivers Head

System Operation 120 Milliseconds (0.12 Sec) After Impact After about 120 milliseconds the driver will be thrown back in their seat. The airbag will have discharged to a great extent, through vents and the driver will have unrestricted visibility forwards. Sequence of events for the passenger airbag is similar to that given for the driver’ s airbag. 120 Milliseconds (0.12 Sec) After Impact Drivers Head Moves Back Towards Seat Airbag Deflates

MINI 97 on 1. Driver Airbag. 2. Seatbelt Pre-tensioner 3. SRS Warning Light. Mini 97 on System consists of - Diagnostic Control Unit (DCU) – located under rear seat to the right hand side of the centre tunnel. Front seat belt pre-tensioners – pyrotechnic reel retraction type. Rotary coupling – located behind steering wheel. Warning lamp – located in instrument binnacle, self test – light on for 5 seconds then off. Diagnostic connector. Designated fuse – yellow cover. Diagnostics via Testbook/T4 4. DCU. 5. Rotary Coupler. 6. SRS Harness.

Rover 100 & XW200/400 Driver Airbag Module 2. SRS Warning Light 3. DCU 4. Rotary Coupler Rover 100, 200/400 XW vin System consists of - Airbag,DCU and warning lamp all integral to steering wheel. Specially designated fuse (yellow cover). Warning lamp self test on for 3 seconds then off. Airbag inflates within 30 milliseconds and full inflation and deflation within 0.1 seconds. Rover 200/400 (XW vin) front seat belt pre-tensioners consist of a mechanical device in which the trigger is self contained. Any work to be carried out to the seats, including removal, will require the pre-tensioners being ‘made safe’ by inserting the red key into the designated slot within the pre-tensioner body. Seat belt retraction is approximately 70mm. 5. SRS Harness 6. SRS Fuse 7. Fusebox

Rover 200 96 my Passenger Airbag Module 2. Driver Airbag Module 3. SRS Warning Light 4. DCU Rover 200 96 MY on System consists of - Drivers airbag Optional passengers airbag. Diagnostic Control Unit (DCU) – located in centre console below radio assembly. Buckle type pyrotechnic seat belt pre-tensioners- fired by DCU, retraction 75mm. Rotary coupling – located behind steering wheel. SRS warning lamp – located in instrument pack – self test on for 5 seconds then off. Diagnostic connector Designated fuse – yellow cover. Diagnostics via Testbook/T4. 5. Rotary Coupler 6. SRS Harness 7. Seatbelt Pre-tensioner 8. Seatbelt Pre-tensioner

Rover 400 ED3 Airbag Module 2. SRS Warning Light 3. DCU This system is only fitted to Rover 400 which have drivers airbag only and are non D-series engined vehicles(Honda engined). System consists of : - Airbag, DCU and warning lamp all integral to steering wheel. Specially designated fuse (yellow cover). Warning lamp self test on for 3 seconds then off. 4. Rotary Coupler 5. SRS Harness 6. Fusebox

Rover 400 Twin bag Driver Airbag Module 2. SRS Warning Light 3. DCU 4. Rotary Coupler Rover 400 Twin Airbag Fitted to Rover 400 with D-series engines (Honda engines) and EC3 systems (twin airbag non D series engined). System consists of : - Drivers airbag. Passengers airbag. Rotary coupling – located behind steering wheel. Diagnostic Control Unit (DCU) – located centrally behind front console. Designated fuse – yellow cover. SRS warning lamp – located with instrument pack, self test – light on for 5 seconds then off. Diagnostic connector Seat belt pre-tensioners are reel retraction pyrotechnic type but the triggers are self contained within the units. Before any work is carried out to these units they must be ‘made safe’ as previously described in this workbook. Diagnostics via Testbook/T4 5. SRS Harness 6. Fusebox 7. Passenger Airbag Module

Rover 600 SRS II 1. Airbag Mounting Bolt 2. Steering Wheel 3. DCU LED Rover 600 Up to approximate Vin No 144844 System consists of : - Diagnostic Control Unit and airbag module integral to the steering wheel. Slip ring - located between the steering wheel and the steering column. SRS warning light - located in the instrument panel, self test on for 6 seconds then off. Designated fuse – yellow cover. Diagnostics via LED behind cover on LH of steering wheel – blink codes available via workshop manual or RAVE. NB. The DCU can only show 1 fault code, so it will only indicate the fault with the highest priority. 3. DCU LED 4. Access Panel

Rover 600 SRS III 1. Drivers Air Bag Module 2.Rotary Coupling 3. SRS Warning Lamp 4. Memory Erase Signal Connector 5. DCU 6. Service Check Connector 7. Data Link Connector 8. Passengers Airbag 1 3 2 8 4 5 6 7 Rover 600 vin No 144845 on The system consists of - Drivers airbag. Passengers airbag. Rotary coupling – located behind steering wheel. Diagnostic Control Unit – located behind centre console. SRS warning lamp – located within instrument pack- self test light on for 6 seconds then off. Designated fuse – yellow cover. Diagnostics is via the warning lamp. Accessing the DTC (Diagnostic Trouble Codes) 1. With the ignition switch "off", connect the SCS short connector to the service check connector. Turn the ignition switch "on". The SRS indicator light illuminates for about six seconds and extinguishes. It will then indicate the DTC. The DTC consists of a main code and a sub-code. Up to three different faults can be indicated. Erasing the DTC memory. With the ignition off, disconnect the SCS short connector from the service check connector 6. Connect the SCS short connector to the MES connector 4. Turn the ignition on. The SRS warning light will illuminate for about 6 seconds and go off. Remove the SCS short connector from the MES connector within 4 seconds of the SRS lamp going off. The SRS warning light will illuminate again. Reconnect the SCS short connector to the MES connector within 4 seconds of the SRS light coming on. The SRS light will go out. Remove the SCS short connector from the MES connector within 4 seconds of the light going out. The SRS light will blink twice to indicate the memory has been erased. In the case of a continuous fault the DTC will flash repeatedly. In the case of an intermittent fault the SRS lamp will indicate the DTC once, then it will stay on. Switch the ignition off and on to repeat the DTC.

Rover 800 96 My on Rotary Coupler 2. SRS Warning Light 3. Driver Airbag 4. J1962 Diagnostic Connector 5. DCU Rover 800 96 MY on System consists of - Diagnostic Control Unit – located behind centre console. Driver airbag Passenger airbag Front seatbelt pre-tensioners – Retraction reel pyrotechnic type SRS warning light – located within the instrument pack, self test light on for 8 seconds then off. Rotary coupler – located behind the steering wheel. Diagnostic connector – located RH side of centre console above DCU. SRS harness Designated fuse – yellow cover. Diagnostics via Testbook/T4 7. Passengers Airbag 8. Seatbelt Pre-tensioner (Saloon) 9. Seatbelt Pre-tensioner (Coupe) 10. Connector - Pre-tensioner

Rover 25 R/H Seat Belt Pre –Tensioner DCU L/H Seat Belt Pre – Tensioner Rotary Coupler Drivers Airbag Diagnostic Socket Passengers Airbag Warning Lamp Rover 25 System consists of - Diagnostic Control Unit (DCU) – located centrally under the rear seat cushion Rotary Coupler – located behind steering wheel Driver airbag Diagnostic connector – located RH side of centre console Passenger airbag (where fitted) SRS warning lamp in instrument pack – self test light on for 4 seconds then off Pyrotechnic buckle type front seat belt pre-tensioners Designated fuse – yellow cover. Diagnostics via Testbook/T4

Rover 45 1 & 2 .Thorax Bags 3 & 12. Seat Belt Pre – Tensioners 4 & 11. Side Impact Sensors 5. Rotary Coupler 6. Drivers Airbag 7. Diagnostic Socket 8. DCU 9. Passengers Airbag 10. Warning Lamp Rover 45 System consists of - Diagnostic Control Unit (DCU) – located beneath the centre console near the handbrake. Side (thorax) airbag modules – located within the front seats (where fitted). Pyrotechnic reel retraction type front seat belt pre-tensioners featuring load limiters. Crash sensors - side impact (where fitted) – located on the inner sills in the passenger compartment. Rotary coupler – located behind the steering wheel. Driver airbag. Diagnostic connector – located above drivers pedals. Passenger airbag (where fitted). SRS warning lamp in instrument pack – self test light on for 4 seconds then off. Designated fuse – yellow cover. Diagnostics via Testbook/T4

MGF 1. Driver’s Airbag Module 2. SRS Warning Light 3. Diagnostic Control Unit 4. Rotary Coupler 5. SRS Harness (YELLOW) 6. Fuse/relay Box 7. Passenger’s Airbag Module (Optional) 8. Seat Belt Pre-tensioners 9. Diagnostic Socket MGF & MGTF System consists of - Diagnostic Control Unit (DCU) – located behind centre console under the radio. Driver’s airbag SRS warning light – located in the instrument pack – self test light on for 5 seconds then off. Rotary coupler – located behind steering wheel. SRS harness Designated Fuse – yellow cover. Passenger’s airbag (optional). Pyrotechnic buckle type Seat belt pre-tensioners. Diagnostic socket – located above fuse box. Diagnostics via Testbook/T4

Rover 75 1 SRS Warning Lamp 2 Rotary Coupler 3 Driver’s Airbag Module 4 Crash Sensor – Side Impact (RH Side) 5 Diagnostic Connector 6 Diagnostic and Control Unit (DCU) 7 Crash Sensor – Side Impact (LH Side) 8 SRS System Earth Header 9 Passenger's Airbag Module Rover 75 System consists of - Diagnostic and Control Unit (DCU) – located under centre console rear cubby box. SRS warning lamp in instrument pack – self test light on for4 seconds then off. Rotary coupler – located behind steering wheel. Driver airbag. Diagnostic connector – located above drivers pedals. Designated fuse – yellow cover. Crash sensors – side impact – located on floor member under front seats. SRS system earth header unit – located under centre console. Passenger airbag. Side (thorax) airbag modules – located within the front seats. Pyrotechnic buckle type front seat belt pre-tensioners (reels featuring load limiters). Pyrotechnic retractable reel type rear seat belt pre-tensioners – deleted for introduction of Rover 75 Tourer. Inflatable Tubular Structures (side head impact protection system). Diagnostics via Testbook/T4.

Rover 75 1 Inflatable Tubular Structure (ITS) Airbag (RH & LH) 2 Rear Seat Belt Pre-tensioners (3 Off) 3 Side (Thorax) Airbag – LH Seat 4 Front Seat Belt Pre-tensioner (LH) 5 Front Seat Belt Pre-tensioner (RH) 6 Side (Thorax) Airbag – RH Seat Automatic Lock Retractors (ALR) All passenger seat belts on Rover 75 were fitted with Automatic Locking Retractors (ALR). This is a feature designed to assist in the fitting of child seats. When the seat belt is pulled to its full extension a click will be heard to indicate that ALR is active. The seat belt will now return on a ratchet mechanism to prevent any further extension of the seat belt. Using this mechanism, the child seat can be fitted securely and tightly. To release ALR, the seat belt must travel to its fully home position. This feature has now been deleted.

Diagnostic Safety Precautions DCU Back up Power - Power Down 10 Minute Safe Period Do Not Use Test Meters Other Than Testbook Diagnostic Safety Precautions Remove the ignition key from the ignition switch and observe the system safe time of 10 minutes before commencing work on the vehicle. This allows the energy reserve capacitors in the DCU to discharge fully and prevents accidental deployment of airbags due to mishandling. • Always disconnect the negative terminal at the battery first, followed by the positive terminal. When an airbag module is removed from a vehicle it must be stored temporarily in the boot of the vehicle with its trim cover facing upwards, or within an approved storage container. Ensure the boot/container is secured Pyrotechnic Storage Governed by ‘the Explosive Act’ When Removed From the Vehicle Stored According to Legal Regulations

Diagnostics Diagnostics. Lamp Check The SRS warning lamp illuminates when the ignition switch is turned to position ’II’ in order to provide a lamp check. After approximately 4 seconds, the warning lamp will go out for the remainder of the ignition cycle, providing the SRS system integrity is maintained. The system also checks the condition of the SRS DCU, airbag and pre-tensioner modules and SRS wiring harnesses. System Continuity Fault If one of the following faults are experienced when the ignition switch is turned to position ’II’, the SRS warning lamp will illuminate and remain on for the duration of the ignition cycle: • DCU connector not engaged or faulty • Harness fault • Earth connection fault • Fuse open circuit If a system fault is detected whilst driving, the warning lamp illuminates to indicate that there is a fault with the SRS system. With the warning lamp on, the SRS system may not operate in the event of a collision. While the ignition is on, the diagnostic function of the SRS DCU monitors the SRS system for faults. If a fault is detected, the DCU stores a related fault code in non-volatile memory and switches the earth output to illuminate the SRS warning lamp. A maximum of five faults can be stored in memory along with the timing information associated with each fault. The fault memory is accessible through the use of T4,Testbook. Low Voltage Fault With a supply voltage range fault, the warning lamp is illuminated. When the correct system voltage returns within range, the lamp will extinguish. The warning lamp will remain lit for a minimum of 12 ± 4 seconds. The fault code will be stored in the DCU memory. Intermittent Fault The warning lamp will come on and remain illuminated for the remainder of the drive cycle. The warning light will not illuminate on the next ignition cycle unless the fault re-occurs, but the original fault code will remain stored in memory.

Diagnostics Permanent fault For a permanent fault, the SRS lamp will stay on after the initial warning lamp test and latch on for every ignition cycle until the cause of the fault has been resolved. In addition, the diagnostic system will record the SRS system fault. After detecting a fault, the system may retain some operational capability: • If a fault is detected in a SRS circuit, only that particular circuit is disabled; the other airbag and seat belt pre-tensioner circuits remain operational and will still be deployed in the event of a collision. • If an internal DCU or power supply fault is detected, the complete system will be disabled. • If a fault exists in the SRS warning lamp circuit, the lamp will not illuminate during the lamp check at ignition on, but provided there are no other faults, the system will remain fully operational. T4/Testbook The SRS DCU logs SRS system faults in internal memory, this can be accessed using T4/Testbook via the diagnostic socket . Additional information that can be accessed from the SRS DCU using T4/Testbook connected via the diagnostics socket include: • SRS DCU code number • Evolution number of the hardware, software and diagnostics protocol • Status of the crashed lock mode • Vehicle identification number (VIN) data Diagnostics

Component Replacement Strategy Component Replacement Strategies DCU Rotary coupling Side impact sensor Harness Passengers link harness Mini • N/A 1 Rover 100 Rover 200/400 XW Rover 200 2 Rover Cabriolet,Coupe & Tourer XW 96 My Rover 400 K,L,T series engine pre 97.5 My 3 4 Rover 400 D series engine Pre 97.5 My Rover 400 97.5 My onwards Rover 600 Rover 800 RS Rover 25/ZR 5 Rover 45/ZS 6 7 Rover 75/ZT & ZT-T MGF pre ECD3 MGF ECD3 onwards 5 & 8 Component Replacement Strategy

Component Replacement Strategy Component Replacement Strategies Note 1 - Only replace airbag harness if physical damage is evident. Note 2 - Replace harness link if passenger airbag has deployed. Note 3 - Only replace rotary coupler if passenger airbag is fitted. Note 4 - Replace airbag harness if passenger airbag has deployed or physical damage is evident. Note 5 - Repair airbag harness if physical damage is evident. IMPORTANT: Follow the approved procedure detailed in this bulletin. Note 6 - Replace rotary coupler if the driver airbag has deployed. Note 7 - Replace the side impact sensor if the airbag has deployed on that side. Note 8 - Replace the wiring to passenger airbag if airbag has deployed. IMPORTANT: Follow the approved procedure detailed in this bulletin.

Harness Replacement Strategy Rover 25, 75 MGF (Later ECD3) Cars Have SRS Harnesses Integrated Into the Main Harness Firing Circuits to Be Cut Away and Replaced As Section Rover 45, MGF (Pre ECD3) & All Non Current Vehicles Use Separate SRS Harnesses Replace Relevant Harness HARNESS REPLACEMENT STRATEGY   VEHICLES WITH INTEGRATED SRS HARNESSES All Rover 25, and 75 vehicles and later MGF ECD3 vehicles have SRS wiring integrated within the main harness. With such harnesses it is often impractical to replace the entire main harness to repair damage and this section describes an alternative repair method. If confirmed that the firing circuit wiring is damaged, a section of wiring will require to be completely cut away and replaced with a new firing circuit harness repair section. IMPORTANT: IT IS VITAL THAT ANY WIRING REPAIR UNDERTAKEN IS CARRIED OUT BY A COMPETENT VEHICLE ELECTRICIAN WHILE FOLLOWING CLOSELY THE WIRING CONNECTION INSTRUCTIONS DESCRIBED LATER. VEHICLES WITH SEPERATE SRS HARNESSES All Rover 45, pre MGF ECD3 and non current vehicles have separate SRS airbag harnesses. If these become damaged they can be replaced independently of the main harness.

Harness Repair HARNESS REPAIR TECHNIQUE IMPORTANT: Extreme care MUST be taken when carrying out the wiring repairs described in this section. It is important to read the information in this section carefully before proceeding. Any wiring connections MUST be made by a competent technician using the described tools. This section describes the only MG Rover approved wiring connection technique for vehicles with integrated SRS harnesses. The procedure MUST be performed by a competent vehicle electrician using the described tools. Where solder sleeve type connectors have not been used before, the training exercise MUST be carried out. Only when confident that a good consistent connection can be made should the technique be applied to the vehicle requiring repair. Please note that the solder sleeve connection method described is the preferred method. When performed correctly, it produces a secure and neat connection. However, if the described technique is not followed, failures can occur. Extreme care and close examination is vital. Training exercise: Equipment required: Solder sleeves - part number YZV000010 (a quantity of these are required). Sufficient length of 0.5 mm 2 wire obtained locally. Suitable heat gun (see Tools and equipment). Solder heat pad. Technique: 1. From the sample wire, cut off approximately 20cm and strip 8mm of insulation from one end of each. 2. Prepare heat gun and solder heat pad (see Tools and equipment). 3. Place a single solder sleeve on the solder heat pad and insert the sample wire ends into sleeve so that the bared sections overlap (see illustration 1 and 2). 4. If using the butane fuel heat gun described later, ignite as per suppliers instructions and set heat setting to ‘3’, this is important, a higher setting will produce too much heat.

5. Raise wiring and connector assembly slightly away from heat pad to allow clearance for heat gun, ensure that the wires in connector remain undisturbed. 6. Apply heat to connector by positioning heat gun nozzle close to (but not touching) the connector. NOTE: if using a heat gun with shield attached, take care not to allow shield to touch the connectors insulation. Apply heat initially to connector ends, this will shrink connector tubing to wire and hold the overlapping wires in position, (see illustration 3). Keep heat gun moving along and around connector tube during heat application, this will prevent local heat concentration which can result in insulation burn through. Harness Repair 7. Complete connection by applying heat to the centre section while again keeping heat gun moving to prevent burning through. Continue applying heat until the solder flows (see illustration 4). Remove heat but do not move wiring for at least 1 minute to allow joint to cool. Switch off heat gun. 8. Inspect joint closely for signs of insulation burning, the plastic tubing should feel smooth to touch throughout its length. Confirm that 8mm to 10mm exists between insulated wire ends (as viewed through clear connector tube), any greater than this dimension will indicate that wiring moved during connection process (see illustration 5).

9. To test connection, apply a reasonable force in an attempt to pull wiring connection apart. If wire pulls out of connector, this will indicate that solder flow was incomplete or that wires moved before heat was applied. 10. Continue making further connections on spare wiring until a good consistent connection can be made. 11. Illustrations 6 to 9 represent connections which are unacceptable. They are caused by the following: Illustration 6 –Insufficient duration of heat application, solder has not flowed satisfactorily. Joint may fail If an attempt is made to pull wiring apart. Always apply heat until solder flows. Illustration 7 –Over application of heat to localised areas will cause tube burning. Heat gun must be kept moving and rotating around connector, try removing heat gun shield if fitted. Illustration 8 –Over application of heat to connector centre will cause tube burning and possible solder penetration of the connector insulation (may appear as a spike). Do not over apply heat, keep heat gun moving and rotating around connector, try removing heat gun shield if fitted. Illustration 9 –Connection disturbed following removal of heat. Allow to cool for a minimum of 1 minute before moving wiring. Harness Repair

Harness Repair Rectification Process 1. Remove key from starter switch and wait 10 minutes to allow SRS power back-up power circuit to discharge. Disconnect both battery leads, earth lead first. 2. Remove the wiring protection material to expose the extent of wiring damage and to allow full inspection. If damage clearly extends beyond that which is visible, further dismantling will be required. 3. Obtain correct harness link part and connectors 4. When good undamaged wire is found, go slightly beyond this point to cut out completely the damaged SRS firing circuit wiring. IMPORTANT: If this area appears impractical to access later for re-connection purposes, cut away more wire until an adequate working space can be achieved. If the damaged section terminates at a point adjacent to adjustable / moving components. i.e. adjustable steering column, seat mechanism etc, go beyond this point until a secure static area can be established. 5. Strip 8mm from each of the wire ends to be connected. 6. Overlay new harness link part and route as close as possible to its eventual installed position to establish the required length. 7. Cut harness link to required length and strip 8mm from wire ends. NOTE: Harness link may include the DCU terminal pins, this is a production part condition and will not be required for service repairs, the terminal pin sections must be cut off and discarded. THE TERMINAL PIN SECTION MUST NOT BE RETAINED AND USED FOR CONNECTION DIRECT TO THE DCU. 8. Ensuring correct harness link to main harness wiring colour orientation, prepare the first 2 corresponding wires for connection. Insert wire ends into solder sleeve so that the conductor section of each wire is overlapping. Do not allow wires to move from this position. Harness Repair 9. Using the technique described in the Training Exercise connect wiring together. Ensure connections are confirmed satisfactory as described, i.e. secure with no burn through. IF RESULT IS CONSIDERED UNSATISFACTORY, ALWAYS REMAKE CONNECTIONS. 10. Continue connection technique with remaining corresponding wires. Always stagger connections and ensure that previous connections are temporarily protected and do not become disturbed. IMPORTANT: ALWAYS SHIELD ANY NEW CONNECTION ABOUT TO BE MADE FROM ANY PREVIOUSLY MADE CONNECTIONS BY POSITIONING THE SOLDER HEAT PAD AROUND THE NEW CONNECTION. 11. Carefully position the newly fitted service link harness into the original wiring protection material. Do not change the routing from the original wiring position or allow any section of the new wiring to 'cut corners' so that it becomes diverted from its protection material. ENSURE NEW CONNECTIONS ARE HANDLED CAREFULLY. NO BENDS OR TWISTS SHOULD OCCUR WHEN INSTALLING INTO WIRING PROTECTION MATERIAL. 12. Referring to the appropriate workshop manual repair number, rebuild vehicle with new components. 13. Connect battery leads, earth lead last. 14. Carry out systems check by turning the ignition on and checking that the SRS warning light illuminates than extinguishes after 3 seconds.

Repair Tools & Equipment Tools and equipment: Heat gun types Either an electrical or butane fuel type heat gun can be used providing that the heat produced is not excessive. The heat gun described below is supplied with a shield attachment, this is optional and should be used with care. If the shield is allowed to make contact with the connector burning may occur, therefore this attachment should only be used if the operator is fully confident. Butane Heat gun – This tool can be obtained from Cartool (UK) Ltd, part number 86-008 Cartool (UK) Ltd Unit 3 Sterling Business Park Brackmills Northampton NN4 7EX United Kingdom Tel: +44 (0) 1604 760099 Fax: +44 (0) 1604 760017 e mail: info@cartool.co.uk Solder heat pad (obtain from local sources)   Cartool 86-008

SRS Precautions (Storage) Ensure the Components Are Kept Dry Store Airbag Module With Pad Face up Do Not Allow Anything to Rest on the Airbag Store Airbag Module on a Flat Surface Away From Electrical Equipment, High Heat Source, Oil, Grease and Detergent Storage Precautions Ensure the components are kept dry Store airbag module with pad face up Do not allow anything to rest on the airbag Store airbag module on a flat surface away from electrical equipment, high heat source, oil, grease and detergent Store pyrotechnic devices in an approved steel cabinet, registered with the local authority If no designated storage space area is available, the airbag module should be locked in the luggage compartment for short storage times. The workshop supervisor must be informed

SRS Precautions (Always) Carefully Inspect SRS Components Before Installation Ensure SRS Connectors Are Correctly Mated and Latched Precautions - ALWAYS Carefully inspect SRS components before installation Ensure SRS connectors are correctly mated and latched Carry out any repairs as per workshop manual details Carry only one airbag module at a time Carry airbag modules with the cover facing upwards Use the correct bolts tightened to the specified torque

SRS Precautions (Never) Drop an SRS Component Wrap Arms Around the Airbag Module Attach Anything to the Airbag Cover Attempt to Dismantle Any Component Apply Electrical Power to a Component Unless Directed to Do So by an Approved Test Procedure Precautions - NEVER Drop an SRS component Wrap arms around the airbag module Attach anything to the airbag cover Attempt to dismantle any component Apply electrical power to a component unless directed to do so by an approved test procedure Transport airbag modules in the passenger compartments of vehicles Install components that show signs of abuse Install used parts from another car

Component Disposal Use Tool SMD 4082 Old Pyrotechnic Devices Must Be Manually Deployed Unless Requested by Rover Deployed in Car or on a Bench Tool Self Test Tool Connection Deploy One Air bag at a Time Follow Safety Precautions For component disposal refer to RAVE or relevant workshop manual.