Data Link Malfunction
The engine control module is detecting a problem with the data link communication.
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)
Essentially, the engine's computer is having trouble talking to other systems in the vehicle, which could affect performance or diagnostics.
What the computer is actually seeing
The ECM sees inconsistent or absent messages from the data link. This could include voltage levels outside of expected ranges (typically less than 0.5V or greater than 5V) when querying data from sensors or actuators.
What a healthy reading looks like
Voltage on the data link should be between 0.5V and 5V; communication messages should be received within 500 milliseconds.
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 for any damage, corrosion, or loose connections. Look for continuity with a multimeter.
- 22. Verify that all modules connected to the data link are powered. Check for voltage at the power feed (typically should be around 12V).
- 33. Use a scan tool to check for other related fault codes. If multiple codes exist, address those issues first.
- 44. Check the communication lines for shorts or opens. Use an oscilloscope if available to observe data signal integrity.
- 55. If no wiring issues are found, consider updating or reprogramming the ECM to ensure firmware integrity.
Common causes
- Faulty wiring or connectors in the data link circuit
- Failed or malfunctioning ECM
- Corrupted software or firmware in linked modules
- Short circuits or opens in the communication lines
- Faulty connected modules (such as TCM, ABS, etc.)
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may be drivable, but expect potential performance issues and lack of diagnostics for other faults.
Will this code return after clearing?
It may return if the underlying issue isn't fixed. Prepare for it to come back if there’s a persistent problem.
Why does this code pair with other fault codes?
Data link issues can affect multiple modules, leading to multiple fault codes being triggered simultaneously.
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