What does it mean?
U1193 is a Network (CAN bus, module communications) fault code. It indicates: Loss of Vehicle Immobilizer Module Communications .
Symptoms
- Engine turns over normally but does not fire, or starts and immediately stalls
- Immobilizer or key symbol lit or flashing in the instrument cluster
- The vehicle starts with one key but not the other
- Intermittent no-start that appears in cold or damp conditions
- MIL (check engine lamp) or a security message accompanying the fault
- The immobilizer module missing from the scan tool module list
Likely causes
- Open, shorted or corroded wiring between the immobilizer module and the engine control unit
- Blown fuse, missing supply voltage or a poor ground at the immobilizer module
- Damaged transponder antenna ring at the ignition lock or a broken lead from it
- Weak battery or a large voltage drop while cranking
- Engine control unit or immobilizer module replaced without being programmed and matched to the vehicle
- Key transponder damaged or the key data lost
- Internal failure of the immobilizer module
How to fix it
- Try the spare key first to rule out a damaged transponder
- Measure battery voltage during cranking and check the main cable connections
- Read immobilizer status in live data to see whether the key is recognised and whether authorisation is granted
- Check the fuse, supply voltage and ground at the immobilizer module under load
- Inspect the antenna ring and column harness for damage, disconnection and corrosion
- Test the data line between the immobilizer module and the engine control unit for continuity and shorts
- If any part of the chain has been replaced, perform the correct programming and matching procedure before replacing further parts