What does it mean?
U1111 is a Network (CAN bus, module communications) fault code. It indicates: Lost Communication With Chime Module .
Symptoms
- No seat belt, key-in-ignition, door ajar or lights-on warning tones
- Turn signal or reverse warning sounds missing while the indicators still work visually
- Warning messages in the cluster appear without the matching audible alert
- The chime module is missing from the scan tool module list
- Occasionally a continuous or random chime instead of no sound at all
Likely causes
- Blown fuse or open power feed to the chime module
- Poor ground connection behind the instrument panel
- Broken or shorted bus wiring between the chime module and the body control module
- Corroded or loose connector at the module, often behind the dash where moisture collects
- Internal failure of the chime module itself
- Body control module fault that stops it from addressing the chime module
- Aftermarket audio or alarm installation that disturbed the dash harness
How to fix it
- Scan all modules and note whether only the chime module is missing or several units are offline
- Check the fuse feeding the module and measure supply voltage and ground at its connector
- Inspect the connector for corrosion, spread terminals and moisture damage, then reseat it
- Check the bus wiring from the module back to the network for opens and shorts
- Look at any recent aftermarket audio or alarm work in the dash area and correct improper connections
- Try commanding the chime with a scan tool output test to see whether the module responds at all
- Replace the chime module last, and check for a body control module software update if the fault persists