Possible cause:
WARNING: This page does not describe the selected car, but rather 27 other vehicles, including the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, 2000 Volkswagen Cabrio, 1999 Volkswagen Jetta, and 1999 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.
- DTC 17978 "Engine Control Module (ECM) locked" is stored in DTC memory, i.e.:
CONTROL MODULE FOR IMMOBILIZER DID NOT RE-ACTIVATE THE ENGINE CONTROL MODULE (ECM)!
- Erase DTC memory (function 05) and end output.
- Select control module for anti-theft immobilizer using address word 25.
- Check DTC memory (function 02) and evaluate using DTC table in repair manual, repair malfunctions if necessary.
- After completing repair work and adaptation of components of immobilizer, always conclude by checking DTC memory of Engine Control Module (ECM) and erasing DTC memory if necessary.
- DTC 17978 "Engine Control Module (ECM) locked" is not stored in DTC memory, i.e.:
THERE IS NO MALFUNCTION IN THE ELECTRONIC IMMOBILIZER!
- Troubleshoot according to instructions in engine repair manual.