What it means
A receiving module detected implausible data from the sunroof control module. Position or anti-pinch sensor values fail plausibility checks and are rejected.
How it works
The sunroof control module operates the roof and reports position and anti-pinch information to other modules. A receiving module sets U046A when the reported roof position or anti-pinch data fails plausibility checks and is rejected.
Common causes
Most likely first.
- Module internal fault or sensor input drift
- Software version mismatch after replacement
- Gateway module routing CAN messages incorrectly
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules and save freeze-frame and communication codes to identify which module rejected the sunroof message.
- Compare live sunroof position and anti-pinch status with the roof's actual position and operation, without forcing a jammed roof.
- Inspect the sunroof control module connectors and harness for loose connections, corrosion, water intrusion, or damage.
- Check the roof tracks and accessible position or anti-pinch sensor areas for obstruction or damage that could make reported position inconsistent.
- If the mechanism, wiring, and network appear sound, verify sensor inputs and module software compatibility using the manufacturer's procedure.
Common fixes
- Remove an obstruction from the sunroof track if it is preventing normal movement.
- Repair damaged or corroded sunroof module wiring or connectors.
- Repair or replace a faulty position or anti-pinch sensor confirmed by testing.
- Correct software configuration after sunroof module replacement.
- Repair or replace the sunroof control module if its data remains implausible.
Can I keep driving?
Driving is generally possible if the roof is secure and no other systems are affected, but do not operate a roof that stops unpredictably or has unreliable anti-pinch protection. Make sure the roof is fully closed before driving in rain or at speed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.