Lost Communication With Audible Alert Control Module
Your car's main computer lost its connection to the horn and alert system module, like a phone losing signal to a speaker. The audible alerts (horn, chimes, warnings) may not work properly until communication is restored.
The ECM continuously monitors CAN bus communication signals to the audible alert control module at regular intervals. If no valid response is received within a specified timeout window, the ECM logs a communication fault and disables audio warnings as a failsafe.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CAN Bus Message Response Time | < 100 milliseconds | > 500 milliseconds or no response |
| Module Handshake Status | Active/Valid signal detected | No valid signal or missing heartbeat |
Code U0160 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, U0160 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.