Brake Booster Motor A Phase U-V-W Circuit/Open
Open circuit on one of the three U/V/W phases of brake booster motor A (3-phase BLDC motor in electric brake boosters).
Affected components
- Brake booster motor a
- Motor phase wiring
Common causes
- High likelihood: Phase wire open or motor winding open
- Low likelihood: Pin pushed back out of connector body
- Low likelihood: Cracked solder joint inside the module or sensor
Possible symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Diagnostic notes
- The malfunction indicator lamp may illuminate
- Reduced-power or limp mode may occur
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.