C0538Motor Control B Circuit Low
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- Motor control B reads low: a channel-B output is held near ground. Besides a direct short of a motor lead to the body, the Bosch patent US5329238 also covers the case where both terminals deviate at once while driven, which it reads as a short across the motor itself or between its two lines. Driver chips such as TI's DRV8873-Q1 react to a short to ground through their overcurrent protection and switch the half-bridge off. J2012 does not tie the code to a specific motor and no public manufacturer assignment of C0538 appears in the sources reviewed. Inspect harness routing near moving parts and connectors for water before replacing the motor or module; channel A uses C0533 for the same fault.
- What you may notice
- Warning lamp of the affected system on
- Motor B does not start
- Likely causes
- LikelyMotor B lead shorted to body near moving parts
- PossibleShort across motor B or between its two lines
- RareWater in the connector of motor B
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.