U0275: Lost Communication With Lighting Driver Control Module C
What to do
Check what is actually lit, from outside the car, at night. If required lighting is out, the car should not be driven in the dark regardless of what the repair costs.
On a vehicle with adaptive or matrix headlights, ask three questions before agreeing to anything — these are complex and expensive assemblies, and the answers vary a lot between vehicles:
- Can the driver module be supplied on its own, separately from the lamp? Sometimes yes, sometimes no, and the difference is substantial.
- Is the module actually faulty, or has it just lost its power or earth? A wiring repair and a headlamp assembly are very different bills.
- Are refurbished or aftermarket units an option for your vehicle? Often not for lighting this complex, but worth asking.
See U0274 about adaptive beams: if part of the control is lost, your lights may be dazzling oncoming drivers without anything inside the car telling you.
What this code means
The third lighting driver control module has stopped being heard from. See U0273 for what these modules do and U0274 for the partial-lighting symptom.
A third driver means the lighting installation is extensively segmented, which in practice means a vehicle with adaptive matrix headlamps, animated indicators, or full-width light bars front or rear.
The observation worth making at this point is about repair economics rather than diagnosis, because it is where owners of these vehicles are most often caught out. Complex lighting is expensive lighting. A matrix headlamp assembly can be among the most costly single parts on a vehicle — occasionally exceeding the value of an older car outright — and the drivers behind them are frequently integrated into the assembly rather than supplied separately.
Three questions are therefore worth asking before authorising anything, and they are reasonable questions rather than awkward ones:
- Is the driver available separately from the lamp? On some vehicles it is, on others it is not, and the difference is very large.
- Is it the driver or the supply to it? A module reporting nothing may simply have lost power or earth, and that is a wiring repair.
- Are aftermarket or refurbished assemblies an option here? For lighting this complex the answer is often no — but it is worth asking rather than assuming.
And the roadworthiness point from U0273 stands regardless of cost: if the lighting the vehicle is legally required to show is not working, it should not be driven in the dark, whatever the quote turns out to be.
Likely causes
Start here
- Water ingress into module · moderate
- Corroded or loose connector · easy
- Failed power or earth supply to the module · moderate
- Heat damage to sensor or wiring · moderate
Less common
- Damaged wiring harness · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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