What it means
The reporting module has lost communication with digital disc player/changer module C. It sets this code when expected messages from that module are not received for a specified time.
How it works
Digital disc player/changer module C supplies disc playback functions for its assigned audio zone or system and communicates its status over the vehicle network. U0189 is set when the reporting module does not receive module C's expected messages for the specified time. It identifies a communication problem with module C specifically, not modules A or B.
Common causes
Most likely first.
- Module power or ground fault
- Damaged or corroded network wiring or connectors
- CAN bus short or open circuit
- Disc player/changer module failure
- Low battery voltage
Symptoms
- Disc playback unavailable
- Audio system warning or error message
- Other communication codes
How to diagnose it
- Scan all modules and review freeze-frame data and communication codes to see whether the fault is isolated to disc player/changer module C.
- Check the audio system for an error tied to module C and confirm which disc playback functions are unavailable.
- Inspect module C's connector and nearby power, ground, and CAN wiring for corrosion, loose terminals, or physical damage.
- Verify module C's power and ground under the manufacturer's specified conditions and note any low-voltage event in the freeze-frame data.
- Test the CAN connection to module C for opens, shorts, or communication faults according to the wiring diagram and manufacturer specifications.
- If its supplies and network pass, use vehicle-specific diagnostics to assess module C and gateway message routing.
Common fixes
- Correct a weak battery or charging fault if low voltage is present.
- Secure or repair module C's connector and terminals.
- Repair damaged power, ground, or CAN wiring serving module C.
- Correct a verified CAN network or gateway routing fault.
- Replace or configure disc player/changer module C only after circuit and network checks pass.
Can I keep driving?
The code usually affects disc playback rather than vehicle control, so the vehicle is generally driveable. If other modules also report communication problems or additional functions fail, investigate the wider electrical fault.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.