Data Link Communication Error
There's a communication error in the data 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 various systems in your vehicle aren't talking properly, which can lead to several issues including trouble with the engine control unit or other modules.
What the computer is actually seeing
The control unit sees missing or out-of-range data from other modules connected via the data link. It usually expects a regular signal response within milliseconds but may see none or corrupted data.
What a healthy reading looks like
The system expects consistent communication at predefined intervals, typically every few milliseconds depending on the module involved.
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. Inspect the wiring and connectors of the data bus for damage or corrosion.
- 22. Confirm the power and ground signals to the control modules are present (typically 12V for power, and close to 0V for ground).
- 33. Use a scan tool to check for other active codes related to the data bus. If present, address those first.
- 44. Disconnect each module one-by-one to identify if one is causing the communication issue. Pay particular attention to modules that were recently replaced or serviced.
- 55. If all connections are good and no modules show failure, reflash or update the software on affected modules.
Common causes
- Faulty wiring or connectors in the J1939 network
- Failed control module
- Corroded or loose connections
- Software issue in one of the modules
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to avoid driving as this can lead to loss of engine performance or other failures.
Will this code come back after I reset it?
If the underlying issue isn't fixed, it will likely return.
Why does this code sometimes pair with other codes?
Multiple modules may fail to communicate due to a common wiring issue or a failing module.
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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