Data Link Communication Fault
Indicates a failure in the data link communication system.
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)
There’s a problem with how the engine control unit (ECU) talks to other parts of the vehicle. This can cause major issues like stalling or not starting at all.
What the computer is actually seeing
The ECU sees that it’s not receiving or sending the correct messages through the communication network, usually due to a loss of signal or a fault in the circuit.
What a healthy reading looks like
Voltage on the data link should be between 2.5V and 3.5V when the system is active, with no more than 0.5V ripple.
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 the data link. Look for signs of fraying, corrosion, or disconnection. Decision: Are they intact? If yes, proceed to step 2. If no, repair or replace.
- 22. Measure the voltage on the data link circuit while the ignition is on. Voltage should be between 2.5V and 3.5V. Decision: Is voltage within range? If yes, proceed to step 3. If no, check the wiring and connections again.
- 33. Inspect the other modules connected to the data link for faults or error codes. Use a scan tool to check for any additional codes. Decision: Are there other codes present? If yes, address those issues first. If no, replace the ECU.
Common causes
- Faulty wiring or connectors in the data link circuit
- Malfunctioning ECU
- Problems with other connected modules or sensors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Driving with a data link communication fault isn't safe; it can lead to unexpected vehicle behavior.
Will this fault code come back after clearing it?
If the underlying issue isn't fixed, yes, it will return.
Why do I see this code with a specific other code?
Often, one fault on the data link can cause multiple codes to appear, as it affects communication throughout the system.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →