High-Speed CAN Communication Bus Fault
There is a communication problem on the high-speed CAN bus.
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 vehicle's computer tried to send or receive data through the high-speed CAN bus but didn't get a response or detected interference. It’s like trying to talk to someone and they don’t respond back, which messes up the conversation.
What the computer is actually seeing
The computer detects that the data packets on the CAN bus are not operating correctly, usually not receiving a signal when expected or noticing unusual voltage levels.
What a healthy reading looks like
High-speed CAN bus should have voltage levels around 2.5V at idle and can swing between 0V and 5V during data transmission. A signal typically operates at 250 kbps.
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 condition of the wiring harness for the CAN bus; look for signs of damage or corrosion. Decision: Are there visible issues? Yes: Repair the wiring; No: Proceed to next step.
- 22. Inspect all connectors for solid connections; look for bent pins or corrosion. Decision: Are connectors clean and tight? Yes: Proceed to next step; No: Clean or replace connectors as necessary.
- 33. Use a scan tool to monitor live data from the CAN bus; check for consistent data transmission from all modules. Decision: Is data flowing correctly? Yes: Issue may be intermittent; No: Replace the suspected faulty module.
- 44. Isolate modules one by one, by disconnecting them from the CAN bus and checking for restored communication. Decision: Did communication return after disconnecting a module? Yes: Replace that module; No: Continue checking other modules.
Common causes
- Wiring issues such as shorts or opens in the CAN bus harness
- Faulty CAN bus module or control unit
- Bad connectors or corrosion at junction points
- Interference from aftermarket electronics
- Damaged sensors sending erratic signals
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive but watch for erratic behavior in the electronics; fix it soon to avoid further issues.
Will this fault come back?
Yes, if the underlying cause isn’t fixed, it will likely recur.
Why does this code appear with other codes?
Many systems share the same bus; a fault in one can affect communication with multiple other systems.
Working a real vehicle right now?
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