1. Ford EEC IV
Operation and Testing

2. Overview A/F Mixture Ignition Timing Idle Speed Thermactor Airflow
Canister Purge
EGR Flow
TCC
AC Fan
WOT Cut Off
Inlet Air Temp
Fuel Pump Relay
Turbo Boost
ECT
MAP/BARO
TPS
CKP/CMP
O2S
EGR Position
ACT KS
BOO AC
Power Steering
PCM

3. Operating Modes Base Engine Strategy MPG Lean Cruise
Modulator Strategy
Limited Operational Strategy
Adaptive Strategy

4. Base Engine Strategy Used to control warm engine running
Open Loop starts at 130o
Warm up mode sub modes
Cranking
Closed-throttle
Part throttle (closed loop)
Wide-open throttle (WOT)
PCM controls actuators for good driveability

5. MPG Lean Cruise Some engines beginning 1988 Certain criteria are met
Goes out of closed-loop fuel control
Very lean for economy at cruise

6. Modulator Strategy
Conditions that require significant change from Base Engine Strategy
Cold engine
Overheated engine
High altitude

7. Limited Operational Strategy
Component Failure
Protect other components
Converter
Substitute values from another sensor
MAP TPS
ECT IAT
EGR Disable EGR

8. Adaptive Strategy Started in 1985 PCM has base map
Monitors operation and modifies base map
Compensates for wear etc.
Dirty Injectors
Are in response to O2S
Stored in KAM

9. Adaptive Strategy

10. Adaptive Strategy

11. Adaptive Strategy

12. Adaptive Strategy

13. Inputs A/F Mixture Ignition Timing ECT Idle Speed MAP/BARO TPS
Thermactor Airflow
Canister Purge
EGR Flow
TCC
AC Fan
WOT Cut Off
Inlet Air Temp
Fuel Pump Relay
Turbo Boost
ECT
MAP/BARO
TPS
CKP/CMP
O2S
EGR Position
ACT KS
BOO AC
Power Steering
PCM

14. Engine Coolant Temp Thermistor Voltage to PCM is 4.5 cold to .3 hot
Resistance 470K cold to 1k hot
Influences PCM’s calibrations for
A/F Raito
Idle Speed
Thermactor Air
Canister Purge
Choke Voltage, Temp compensated accel pump
Upshift light

15. Pressure Sensors MAP, BARO Pressure-sensitive capacitor
Convert to frequency out
100 Hz no load Idle
159 Hz atmospheric (WOT)
Voltage will go from 0 to 5 at the frequency above

16. Pressure Sensors MAP used for BARO BARO used with Vane Airflow Sensors
PCM uses Key On before cranking and WOT for BARO calculations.
BARO used with Vane Airflow Sensors
Looks like MAP with collar

17. Throttle Position Sensor
Some adjustable, some not
Potentiometer
3 wires, 5v reference, ground, signal
Two common problems
Bad spot, signal dropout
Bad ground
Full reference on signal
Biased high

18. Profile Ignition Pickup (PIP)
Hall Effect Switch
Engine speed and crank position
In distributor
One vane narrower for location

19. Profile Ignition Pickup (PIP)
On DIS sensor is on front of engine
One vane for each pair of companion cylinders
Most PIP signals go from .4v or less to battery voltage at 10o BTDC

20. Cylinder Identification (CID)
Used with Distributorless Ignition
PIP doesn't know which stroke
Driven at cam speed
Also used for SFI

21. 4 Cylinder PIP CID On DIS, 1 & 4 fire together
CID is on crank with PIP

22. Ignition Diagnostic Monitor
Used on TFI systems
Checks to see that spark occurred
Wire with 22k from Tach wire to PCM
Makes sure SPOUT command is carried out
Makes sure timing advance is working

23. Knock Sensor (KS) Piezoelectric type Vibration sends signal to PCM
PCM retards timing 1/2o per engine revolution

24. Intake Air Temp Sensor (IAT)
Was called Air Charge Temp (ACT) before OBDII
Thermistor
Voltages and resistance same as ECT
A/F and advance
Used on most Fords

25. EGR Position (EVP) Feedback (PFE)
EVP Linear Potentiometer
only monitors position
EVP Black and White physically interchangeable
PFE is like MAP but gives a voltage
Measures exhaust pressure under EGR valve
PFE measures flow used to
Fine tune EGR position
Fine tune A/F ratio
Modify ignition timing

26. Vane Air Flow (VAF)
Used with VAT and BP to calculate Speed Density

27. Mass Airflow MAF Beginning in 1988 Uses sample tube Uses hot wire
Encased in Glass
200o above ambient
A/F and Timing

28. Transmission Switches
PCM knows if in gear, park or neutral
Affects Idle air control strategy
For A/T because converter loads engine
Response to rapid throttle closing

29. Transmission Switches
AXOD uses 3 switches
Neutral Pressure NPS
Trans Hydraulic THS 3-2
Trans Hydraulic THS 4-3
AXOD Trans Temp TTS opens over 275oF
Will apply TCC if temps get high like uphill climb
Can tell which gear except if it is in 1 or 2

30. Transmission Switches

31. Transmission Switches
Manual Trans
Neutral Gear Switch NGS
Clutch Engaged Switch CES
Wired in parallel so both must be open for PCM to know car is in gear.

32. Brake On/Off BOO In stop lamp switch
A4LD has PCM controlled converter lockup
Used on most models today
Increases idle when in gear and brakes are on
May disengage AC on prolonged idle

33. Vehicle Speed Sensor (VSS)
Speedometer output
Mechanical or electric speedometer.
8 cycles per revolution
signals per mile
Used for
TCC lockup
Coolant fan control
Identify deceleration

34. Other Inputs Power Steering Pressure Switch PSPS AC Demand (ACD)
Opens between 400 and 600 PSI
Increases idle speed
AC Demand (ACD)
AC Clutch Cycling Switch (ACCS)
PCM watches to increase idle speed

35. Outputs A/F Mixture Ignition Timing Idle Speed Thermactor Airflow
Canister Purge
EGR Flow
TCC
AC Fan
WOT Cut Off
Inlet Air Temp
Fuel Pump Relay
Turbo Boost
ECT
MAP/BARO
TPS
CKP/CMP
O2S
EGR Position
ACT KS
BOO AC
Power Steering
PCM

36. Air / Fuel Mixture Control
Three types
Feedback Carburetors
Central Fuel Injection (TBI)
Electronic Fuel Injection (PFI)
Non Sequential
Group
Sequential

37. Feedback Carburetors
Motorcraft & Carter uses solenoid to bleed air into idle and main metering circuits

38. Holley Carburetors
Holley uses remote solenoid with similar idle control

39. Holley Carburetors
Uses vacuum diaphragm and valve for main metering control

40. Central Fuel Injection
Low Pressure System
Single injector
Two injectors
Alternates injectors
ECM grounds to turn on
Pulse Width Modulated

41. Central Fuel Injection

42. CFI Fuel Delivery

43. Port Fuel Injection (EFI)

44. Port Fuel Injection Non-sequential (EFI) Group or bank-to-bank
Two Groups
Sequential (SEFI)
Injectors pulsed one at a time in firing order
Used throughout product line by early 1990s

45. Injector Removal

46. Fuel Supply System

47. Fuel Supply System Fuel Pump In tank
Trucks may have a lift and pressure pump
Most are around 39 psi
Pressure relief at 100 psi

48. Fuel Supply System Pressure regulator Manifold pressure modified
Low of 30 around psi (deceleration)
High of 39 psi (WOT)
Turbocharged may go as high as 50 psi
CFI does not use manifold pressure.
High pressure psi
Low pressure 14.5 psi

49. Fuel Supply System Fuel Pump Relay PCM Controlled
Turns on with key for 1-2 seconds or until PIP signal is present.
Inertia Switch is in series with pump

50. Thick Film Integrated (TFI-IV)
Thick film refers to the type of semi-conductor
Controls spark primary
Sends PIP to PCM
PCM modifies and sends back SPOUT
SPOUT tells TFI when to turn primary on and off.
In distributor or “Closed Bowl”

51. Thick Film Integrated (TFI-IV)

52. Thick Film Integrated (TFI-IV)
TFI Module
Closed Bowl
Octane rod can change base timing while keeping rotor right.

53. Distributorless Ignition
PCM controls dwell and timing
DIS module is like TFI module
Also uses SPOUT
Now called Spark Angle Word (SAW)
1991 second generation using Reluctance instead of Hall sensors
35 teeth on crank 36 minus1 for position

54. Distributorless Ignition
Base Timing Check
Remove SPOUT/SAW jumper
10o
Self check adds 20o
Octane adjustment jumper looks like SPOUT
Retards 3o to 4o and can be left out

56. Spout Connectors

57. Idle Speed Carbs & CFI use Act as Idle Dashpot Throttle kicker
DC motor idle speed control (ISC)
Idle Tracking Switch
Senses closed throttle
PCM then operates ISC
Act as Idle Dashpot

58. EFI Idle Speed Control Air bypass solenoid PCM Controlled
Duty Cycle pintle valve
Also a dashpot

59. Thermactor Air Management
Thermactor Air Bypass (TAB)
Thermactor Air Diverter (TAD)
PCM Controlled

60. Thermactor Air Management
CTS Below 50o TAB grounded
Sends air to atmosphere
Between 50 and 190 Bypass valve sends air to diverter and to manifold
Over 190 closed loop and air goes to Cat
Bypass at idle, WOT, and with failing O2S

61. Open Loop Tip
The fastest way to see if vehicle is in open loop is to see where the air is going
Cat = Closed Loop
Atmosphere or manifold = Closed Loop
Provided thermactor system is working

62. Canister Purge Three types Constant purge with no PCM control
PCM controlled in-line solenoid
PCM controlled with temperature controlled vacuum valve

63. Canister Purge/Heat Control
To valve that warms intake manifold

64. EGR Control
EGR Control and EGR Vent
2 solenoids that are “dithered”

65. EGR Control EGR Shutoff Solenoid
Uses one solenoid
Controls ported vacuum
EGR Shutoff Solenoid with Backpressure Transducer
One solenoid
Strength of vacuum controlled by transducer
Does not have EVP sensor

66. EGR Control Vacuum Regulator
Introduced in 1985 and is used for most applications

67. Notice the safety glasses 
EEC IV Diagnosis
Codes follow self test
Codes can be read
Manually
Watch MIL
Hook up meter
Star II
Other scan tool
Notice the safety glasses 

68. Slow and Fast Codes Slow codes can be read with pulsing meter or MIL
Fast codes can be read by scan tool
Fast codes precede slow and look like a momentary flashing.

69. Diagnostic Connector

70. KOEO Self Test Procedures
Engine warm
Turn off for 10 seconds
KOEO, then ground STI
Test will run, then read codes
All accessories off
2.5L and 4.9L hold clutch fully in.

71. KOEO Self Test Codes

72. KOER Self Test Procedures
Engine warm 2000 RPM 2 min
Turn off for 10 seconds
KOER, then ground STI
Test will run, then read ID codes
Push brake and turn steering wheel
After code 10 (or 1 flash) snap WOT

73. KOER Self Test Codes

74. Computed Timing Pull SPOUT/SAW Reinstall SPOUT/SAW Run KOER self test
Check for 10o with timing light
Reinstall SPOUT/SAW
Run KOER self test
At end of last code, 20o will be added to base timing for 2 min.

75. Other Tests Continuous monitor (wiggle) SEFI Cylinder Balance
After last code, deactivate and reactivate self test
Wiggle wires etc. Fault will display
SEFI Cylinder Balance
KOER after last code, tip throttle and release.