Quick Reference: Immobilizer III Service Procedures
Installing/Adapting a used Engine Control Module (ECM)
It is possible to try used ECMs for diagnosis purposes as long as they have the
correct part numbers. You will need to retrieve the VIN and 14 digit Immobilizer Serial
Number for the used component and for the vehicle you’re installing the parts on
before you begin. Replace only one component at a time. Replace the used part
with the original before trying a different component.
1. Measure battery voltage. (It should be maintained at 12.5 volts or higher.)
2. Obtain and record the Immobilizer PIN of the used ECM.
3. Obtain and record the coding from the ECM of the vehicle you’re working on.
4. Obtain and record the Immobilizer PIN from the ECM of the vehicle you’re working on.
5. Remove ECM of vehicle and install used ECM.
6. Connect Scan Tool and select Address Word 01 – Engine Electronics
7. Select Enabling PIN.
8. Enter the 7 digit PIN for the used ECM and press ‘Q’.
9. After confirmation, ECM is ready for use. Press Back Arrow to get back to
the function screen.
10. Select Adaptation Channel 50 PIN.
11. Enter the 7 digit PIN for the vehicle you’re working on.
12. Press ‘Q’ and wait until VIN and Immobilizer Serial Number are displayed
on Scan Tool.
13. Check that the VIN displayed on the Scan Tool matches VIN of vehicle.
14. Press ‘Save’ and then ‘Accept’.
15. Switch ignition off and then back on within one minutes but
DO NOT START THE ENGINE FOR TWO MINUTES.
16. Check that each key starts vehicle waiting at least 2 minutes between keys.
17. Make sure the ECM coding (Function 07) is correct.
18. Perform ‘00’ scan – ‘Interrogate all fault memories.’
19. Clear all relevant DTCs.
20 Adapt throttle and kickdown.
21. Set Readiness Code.
If installing the used ECM does not repair the vehicle you’re working on, remove
it and re-install the original ECM before attempting further repairs.

VWoA Service Training / Technician’s Helpline
6/11/02