Control Module Communication Bus Off
The control module is unable to communicate over the bus network.
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 control module isn't talking to other modules like it should—think of it like a phone that can't connect to the network.
What the computer is actually seeing
The computer detects that messages are not being received from or sent to other ECUs on the communication bus for a certain period.
What a healthy reading looks like
Bus communication should be active and stable, with voltages typically around 2.5V to 5V on the CAN bus lines while the vehicle is on.
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 the wiring and connectors of the communication bus for damage or corrosion.
- 22. Verify power and ground are present at the control module—should be around 12V for power and close to 0V for ground.
- 33. Use a scan tool to check if other control modules are communicating correctly; if they are, focus on the control module in question.
- 44. Inspect for any visible damage to the control module; if all else checks out, consider swapping with a known good module. If communication restores, the original module is faulty.
Common causes
- Faulty wiring or connectors in the communication circuit
- Failed control module(s)
- Electrical interference from other components
- Module power issues
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, if the control module is not communicating correctly, vehicle systems may be compromised, affecting safety.
Will this code come back after clearing it?
If the underlying issue is not fixed, the code will likely return after clearing.
Why might this code pair with others?
Issues with bus communication can affect multiple modules leading to related codes being triggered.
Working a real vehicle right now?
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