Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P057A Brake Pedal Position Sensor A Circuit/Open

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The brake pedal position sensor is an analogue 5 V sensor, usually Hall-type, giving the pedal position continuously instead of a switch – for brake lights, cruise control, stop-start, brake-throttle override and regenerative braking. GM (from about 2012) and Stellantis read it in the engine module, Saab's 9-4X and 9-5 in the body module; its learned rest position (about 1 V) must be relearned after replacement. P057A is the general circuit or open-circuit fault. No manufacturer document available to us uses it; GM reports an open circuit as P057C or P057D depending on the line, type A with one trip, and sets the pedal position to 0 %. Brake detection then relies on the brake light switch.

Likely causes

Connector at the sensor loose or corroded, pins pushed back
5 V reference, signal or ground line open
Sensor faulty internally
Engine or body module

Symptoms

  • Check engine light on
  • Cruise control and stop-start inoperative
  • Possible power reduction

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–250
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

brake pedal position sensorsensor wiringengine control module

Related codes

P057BP057CP057DP057EP0504

References: law.cornell.edu, gsi.ext.gm.com, gm-techlink.com.