1. Concept of ACSF TAN (Type Approval Number)
Principle: If software has an impact on type approval, the software versions of all impacted ECUs are covered by one TAN Type Approval Number for each system type approval.
Example: Regulation ECE 79 with ACSF Automatically Commanded Steering Functions (important base for automated driving)
=> see next page (document ACSF-08-10)

2. ACSF proposal: Document ACSF-08-10
Requirement: It shall be possible to confirm the valid software identifier of the system by reading out the ACSFTAN via the use of an electronic communication interface or other fitted on-board system (e.g. display).
At the time of Type Approval the means implemented to protect against simple unauthorized modification to the operation of the verification means chosen by the manufacturer (e.g. warning signal) shall be confidentially outlined.
The manufacturer shall provide the ACSFTAN including the chosen strategy to determine the ACSFTAN in the information package.
The manufacturer shall provide information how to read out the ACSFTAN during periodic technical inspection.
In case the type approval relevant software parts of an ACSF are modified by the vehicle manufacturer, the ACSFTAN shall be updated according to the chosen strategy leading to a type approval extension. Modification of software parts are type approval relevant if they lead to a modification of the type regarding the Annex 6 of this Regulation or if functionalities are extended regarding the system information data.

3. Link between SW versions of different ECUs and ACSF TAN
Example: 4 ECUs have an impact on the type approval of ACSF
Update w/o TA impact
Update with
TA impact
Type approval test
First registration
ECU
SW version 1
V3.6 2
V1.3 3
V1.6 4
V8.9
ECU
SW version 1
V3.9 2
V1.4 3
V1.6 4
V9.1
ECU
SW version 1
V4.1 2
V1.8 3
V2.3 4
V9.3
ECU
SW version 1
V5.0 2
V1.8 3
V2.7 4
V9.8
R Ext 00
ACSF TAN 0023
R Ext 01
ACSF TAN 0024
The same principle than for some today Hardware Updates today (part number may change, but not type approval)
The system for vehicle recalls in case of safety problems is the same as today. No direct link with the TAN.

4. New SW version available with impact on TA
Need to type approve SW update for new vehicles before update of registered vehicles
Vehicle owner gets information that type approved SW update is available
New SW version available with impact on TA
Vehicle owner wants to update the vehicle
System type approval information document
ACSF TAN 0023
Extension of type approval
New system type approval information document
ACSF TAN 0024
Vehicle manufacturer informs authorities that TAN 0024 is authorized for after-market update
System type approval certificate R79
00322 Ext 00
New system type approval certificate R79
00322 Ext 01
Vehicle is updated with secured process
Information to Type Approval Authority
Authorities can check during PTI whether the TAN on the vehicle is authorized
Legend:
Blue: UNECE process
Green: national process