What it means
A receiving module detected implausible data from mirror control module B. Mirror position, fold/unfold state or heating values fail plausibility checks and are rejected.
How it works
A receiving module checks messages from mirror control module B about mirror position, folding state, or heating. U044F sets when a reported value fails the receiving module’s plausibility checks and is rejected; the code alone does not confirm that the mirror module itself is faulty.
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 logged U044F and what mirror-related data was rejected.
- Check whether mirror B adjusts, folds, or heats as expected, and compare its physical state with the status shown on the scan tool.
- Inspect mirror B’s housing connector, door harness, and module wiring for damage, loose terminals, or signs of water entry.
- Use a scan tool to compare mirror position, fold-state, or heating data from module B with the actual mirror behavior.
- Check for recent mirror, door module, or control module replacement and verify software compatibility and configuration.
- Test the mirror module’s power, ground, and communication circuits using wiring information and manufacturer’s specifications.
Common fixes
- Reconnect or repair a loose, corroded, or damaged mirror B connector or door-harness wire.
- Repair a faulty mirror position or fold-state input if testing identifies one.
- Correct module configuration or software compatibility after mirror or module replacement.
- Repair a confirmed power, ground, or communication circuit fault.
- Replace mirror control module B only if its wiring, inputs, and configuration are sound and invalid data persists.
Can I keep driving?
If mirror B cannot be positioned to provide a clear view, do not drive until you can see safely using the required mirrors. If only a nonessential heating or folding feature is affected and visibility is adequate, a cautious drive may be possible.
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.