Data Link (DLC) Failure
The vehicle's communication link is faulty.
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 truck can't talk to its computer systems properly, often because of a broken wire, bad connectors, or an issue with the computer itself.
What the computer is actually seeing
The vehicle's ECM expects a certain data communication frequency and voltage levels but receives erroneous signals or no signals at all, typically at a 0-5V range for a proper signal.
What a healthy reading looks like
Normal operation should show consistent data exchange with voltage levels between 0.5V to 4.5V on the data link pins.
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 visible damage to the DLC wiring and connectors.
- 2Using a multimeter, verify the voltage on the DLC pins. Expected range is 0.5V to 4.5V with proper communication.
- 3Inspect the integrity of the connectors; clean or repair as necessary.
- 4If no faults are found in wiring or connectors, use a scan tool to check if other codes are present that could point to a specific module issue.
- 5If all else fails, consider testing or replacing the ECM.
Common causes
- Damaged wiring in the data link harness.
- Corroded or loose connectors at the DLC or ECM.
- Faulty ECM or other control modules.
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's not recommended, as communication issues can prevent essential systems from working.
Will this code come back after clearing it?
Yes, if the underlying issue isn't fixed.
Why does this code pair with other codes?
Communication faults can affect multiple systems, leading to multiple codes being logged.
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