OBD-II code · Chassis
C056D Brake Pedal Position Sensor Supply Voltage Circuit Low
Brake pedal position sensor supply voltage below expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with C056D?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySupply wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Pedal Sensor, Sensor Supply
Related codes
- C056ABrake Booster Pressure Sensor Power Supply Circuit
- C056BBrake Pressure Sensor A Intermittent/Erratic
- C056CBrake Pressure Sensor B Intermittent/Erratic
- C056EBrake Pedal Position Sensor Supply Voltage Circuit High
- C056FBrake Booster Travel Sensor Circuit Low
- C0570Brake Booster Travel Sensor Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.