U046A code meaning
Invalid Data Received From Sunroof Control Module
What U046A means
U046A is logged when a module, usually the body controller or the overhead console, gets data from the sunroof control module that fails its checks: position and motion reports that contradict each other, a counter that stops changing or a bad checksum. The sunroof module drives the glass panel and sun blind and tracks their end positions. US standard FMVSS 118 restricts when a power-operated roof panel may close and demands automatic reversal where it closes outside those conditions, so a receiver that cannot trust the module usually blocks convenience closing from the key fob or rain sensor. No manufacturer documents U046A publicly. U0169 means the module is silent, U0140 concerns the body control module. Besides connectors, water from blocked roof drains is a plausible cause. The roof may ignore its switch; no MIL.
U046A at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U046A
- Sunroof does not open or close with its switch
- Convenience closing by key or rain sensor no longer works
- Panel stops midway or reverses unexpectedly
Common causes of U046A
- Most likelyWater in the roof module or its connector from blocked sunroof drains
- PossibleLost end-position learning after battery disconnection or panel work
- PossibleChafed wiring or loose connector in the headliner
- Less likelyInternal fault in the sunroof control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Sunroof module
What each part of U046A means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6A | The exact fault in that area. |
What to do next
- Note U046A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U046A
What does U046A mean?
U046A means "Invalid Data Received From Sunroof Control Module". U046A is logged when a module, usually the body controller or the overhead console, gets data from the sunroof control module that fails its checks: position and motion reports that contradict each other, a counter that stops changing or a bad checksum. It is a generic code, so it means the same on every make.
Is it safe to drive with U046A?
U046A does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U046A fail an emissions test?
U046A is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U046A to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will U046A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.