ECM
Engine Control Module (ECM) Versions-Overview
Engine control modules: 4A0 906 266 A
4A0 906 266 AA
4A0 906 266 AB
These are the introductory version and the successor versions for the USA Audi 100 with On Board Diagnostic (OBD I). The engine control modules are downwardly compatible.
The function and structure of the system are described in Self-study Program No.130.
Engine control module: 8A0 906 266 B
With this version, the MFI ECM was completely modified. Important new features are:
- Oxygen sensor control with learning function; CO adjustment on Mass Air Flow (MAF) sensor eliminated.
- Coding of MFI ECM using VAG 1551 scan tool and "Code Control Module" function 07.
Engine control modules: 8A0 906 266 E
8A0 906 266 H
8A0 906 266 J
These are the successor versions of the 8A0 906 266 B control module.
Engine control module: 8A0 906 266 D
With this version, the On Board Diagnostic II (OBD II) was used in the Audi A6 with 2.8 liter V6, manual transmission and front wheel drive. Important new features on vehicles with OBD II are:
- Additional Heated Oxygen Sensor (HO2S) probe after Three Way Catalytic Converter (TWC)
- New engine control module with five individual connectors, total of 96 terminals
New On Board Diagnostic (OBD) program with address word 01 and address word 33.
Engine control module: 8D0 906 266
8D0 906 266 A
These are the successor versions of the 8A0 906 266 D control module with On Board Diagnostic II (OBD II)
Engine Control Module (ECM), Coding
NOTE:
- During Engine Control Module (ECM) identification, a 5-digit code must always be displayed.
- Coding is carried out with the VAG 1551 scan tool.
If coding that corresponds to the vehicle is not displayed or if the ECM has to be replaced, the ECM must be coded as follows:
- Connect VAG 1551 scan tool.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -7- to select "Code Control Module" function 07.
Indicated on display
Rapid data transfer Q
07 - Code Control Module
- Press -Q- button to confirm input.
Indicated on display
Code control module Q
Enter code number XXXXX (0-32000)
- Enter code number for vehicle and press -Q- button to confirm input. Coding variations, See Engine Control Module (ECM), Coding Variations
If the following is indicated on the display:
Function is unknown or ->
cannot be carried out at the moment
A non-released code number has been entered.
8D0906206 2.61 V6/2V MPI OBD2 D01
Coding 01051 WSC 06368
ECM identification and entered coding (e.g. 01051) are shown.
- Press -> button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Press buttons -0- and -6- to select "End Output" function 06.
Indicated on display
Rapid data transfer Q
05 - End Output
- Press -Q- button to confirm input.
Indicated on display
Rapid data transfer HELP
Insert address word XX
NOTE:
The ECM uses the coding that is entered and displayed only after the ignition has been switched off once. Incorrect coding leads to:
- Driving performance problems (jerky shifting, rough load change, etc.)
- Increased fuel consumption
- Elevated exhaust gas values
- Decrease in transmission service life
- Storing of malfunctions that are not present in DTC memory
- Functions are not carried out (oxygen sensor control, triggering of the EVAP canister system, etc.).
Engine Control Module (ECM), Coding Variations
NOTE: The code number will be composed as shown in the following example:
NOTE: Vehicles with traction control (ATC) can be recognized by the ATC indicator light in the instrument cluster and/or by ABS control module identification using the ABS On Board Diagnostic (OBD) program.
Engine Control Module (ECM), Replacing
NOTE:
- By disconnecting the ECM, the permanent voltage supply is disconnected and therefore the learning values, DTC memory and readiness code are erased.
- If uneven idle occurs after the ECM is installed, let the engine idle for a few minutes so that the learning process can be carried out See Basic Setting, display groups 007 and/or 008 Read Measuring Value Block (Function 08)
If the engine control module is replaced, carry out the following work steps in the specified sequence.
- Switch ignition on.
- Connect VAG 1551 scan tool and operate until control module identification is displayed.
ECM identification and the coding are shown on the display.
8D0906266 2.81 V6/2V MPI OBD2 D01
Coding 01051 W8C 06388
- Print out ECM identification and compare coding to table of coding variations.
- Press -> button.
Indicated on display
Rapid data transfer HELP
Select function XX
- Switch ignition off.
- Remove faulty ECM.
- Install new ECM.
- Re-code ECM with appropriate coding from table, See ECM, coding