P057EBrake Pedal Position Sensor A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The brake pedal position sensor A is an analogue 5 V sensor giving pedal travel continuously; its rest position (about 1 V) is learned. GM reads it in the engine module from about 2012 and uses it as an enabling condition of transmission monitors – hence type A, warning lamp after one trip, unlike cruise control codes. On any circuit fault GM sets the pedal to 0 %, so brake detection relies on the brake light switch. P057E means implausibly fast signal jumps within the valid range: GM sets it at jumps above 11 in 5 of 20 samples. Brief interruptions can also make GM's engine module learn a wrong rest position – it then sees the brake pressed and cuts power; GM names fretting at the 5 V reference or signal.
- What you may notice
- Check engine light on (GM)
- Sporadic power reduction when accelerating
- Cruise control cutting out sporadically
- Likely causes
- LikelyLoose contact or fretting corrosion at sensor or inline connector
- PossibleBroken or chafed wire near the pedal
- PossibleSensor worn internally (signal jumping)
- RareInterference on the 5 V reference
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.