Lost Communication with Body Control Module (BCM)
The vehicle's control module cannot communicate with the Body Control Module.
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What it means (plain English)
The Body Control Module (BCM) is like the brain for things like lights and locks. If it can't talk to the rest of the vehicle's computer system, it can't control those features properly.
What the computer is actually seeing
The central diagnostic module detects a communication loss from the BCM, which could be due to wiring, connectors, or the BCM itself failing to send data.
What a healthy reading looks like
The BCM should respond to data requests with a message within 100 milliseconds. If it doesn't reply, you may see this code.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check battery voltage. It should be between 12.4V and 12.7V with the engine off. If low, charge or replace the battery.
- 22. Inspect the BCM connectors and wiring for visible damage or corrosion. Repair any issues found.
- 33. Using a scan tool, check if other modules report communication issues. If yes, it's likely a network problem. If only the BCM is affected, proceed to the next step.
- 44. Test the BCM with a known-good unit or reprogram it if applicable. If communication resumes, replace the BCM.
Common causes
- Faulty Body Control Module
- Damaged wiring or connectors between the BCM and the control unit
- Low battery voltage affecting communication
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity. You may experience issues like inoperable lights or locks but the vehicle should be drivable. Fix it soon.
Will the code come back after clearing?
Yes, if the underlying issue isn't resolved, the code will likely return upon the next key cycle.
Why does this code sometimes pair with U0155?
U0155 indicates a similar communication loss issue, often pointing to a broader problem with the data bus or multiple modules.
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