Brake Booster Motor A Position Sensor Supply Circuit Low
Brake Booster Motor A Position Sensor Supply Circuit Low: the signal voltage is below the expected range. The electric brake booster generates the braking assist; a motor or sensor fault can reduce or disable power-assisted braking. Safety-relevant.
Affected components
- Booster motor a pos sensor supply
Common causes
- High likelihood: Supply wire shorted to ground
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Harness chafing through insulation
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
Related codes
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.