Lost Communication with Body Control Module (BCM)
The Body Control Module is not communicating with the main vehicle computer.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The main vehicle computer isn't getting signals from the Body Control Module, which controls things like lights and locks.
What the computer is actually seeing
The main computer checks for signals from the Body Control Module and finds they are missing after a set time.
What a healthy reading looks like
Normal communication should show constant data exchange voltages between 0.5V and 12V depending upon the signal type.
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.
- 1Check for battery voltage at the Body Control Module connector (should be around 12V). If not, check battery and fuses.
- 2Inspect all wiring and connectors between the Body Control Module and the main vehicle computer for damage or corrosion.
- 3Use a scan tool to check if other modules are communicating correctly. If other modules also show communication errors, suspect the CAN bus system.
- 4If wiring and connectors are fine, test or swap out the Body Control Module with a known good part and see if communication is restored.
Common causes
- Bad wiring or connectors between the main computer and BCM
- Defective Body Control Module
- Corrosion or damage at BCM connectors
- Battery voltage too low causing communication issues
- Faulty CAN bus system affecting communication
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but fix it soon to ensure all features controlled by the BCM are functioning.
Will this code come back even after clearing it?
It may if the underlying issue isn't fixed, like a bad BCM or wiring.
Why does this code sometimes pair with other U-codes?
Other U-codes often indicate communication problems across multiple modules, usually tied to wiring or the CAN bus.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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