What it means
A control module received invalid data from moveable roof control module B. The code identifies a data validity fault; the specific affected function depends on the vehicle.
How it works
Moveable roof control module B sends roof status and control data over the vehicle network. This code sets when a receiving module judges data from module B invalid; the code alone does not identify a particular roof mechanism or function.
Common causes
Most likely first.
- Fault in the transmitting module
- Network wiring or connector fault
- Module power or ground fault
- Software or configuration mismatch
Symptoms
- The moveable roof may not operate correctly
- Related communication codes or system warnings may appear
How to diagnose it
- Scan all modules for codes and freeze-frame data to see which module reported U050B and whether other communication faults are present.
- Check roof operation and warnings associated with module B, and stop the test if the roof is obstructed or not moving safely.
- Inspect module B's connectors and accessible network wiring for moisture, corrosion, loose pins, or physical damage.
- Check module B's power and ground according to the manufacturer's procedure, since unstable supply can affect transmitted data.
- Compare live roof status from module B with the roof's actual position and operation, then verify network signals and module configuration against service information.
Common fixes
- Secure or clean a loose or corroded connector at moveable roof control module B.
- Repair damaged network wiring or a poor power or ground connection to module B.
- Correct a software or configuration mismatch using the vehicle's approved procedure.
- Replace moveable roof control module B if its supply and network are sound and it continues to send invalid data.
Can I keep driving?
If the roof is fully closed and latched and no safety-related warning is present, driving is generally possible; avoid operating the roof until diagnosed. Do not drive with a roof that is unsecured or obstructs visibility.
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.