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

P057C Brake Pedal Position Sensor A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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. P057C means the signal is too low – a short to ground: GM below 5 in 20 of 32 samples. GM bulletins for 2012–14 pick-ups and SUVs name connector X205 under the left defroster duct, with cruise, brake light and stability messages and reduced power.

Likely causes

Connector or terminals at sensor or inline connector (GM X205) loose, pushed back or corroded
Signal or 5 V reference shorted to ground
Sensor faulty internally
5 V reference pulled down by another sensor

Symptoms

  • Check engine light on (GM, one trip)
  • Cruise control, brake light or stability functions restricted
  • Reduced power when accelerating

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–300
Time0.5–2 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

P057AP057BP057DP057EP0571P0572

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.