Powertrain, generic · Hybrid propulsion

P0C54 Drive Motor A Position Sensor Circuit A Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C54 stands for short dropouts or jumps on Circuit A of the motor A resolver that never last long enough to count as a steady low or high fault. No manufacturer documents this code publicly. GM handles the same situation differently: on its 2013 eAssist cars the resolver circuit checks run a retry scheme that lets the drive recover from brief faults, and only light the MIL through P0C52 or P0C53 once the trouble repeats, either about 5 s of failure within roughly 10 s or 10 s of accumulated failure over 30 minutes. Typical triggers are loose terminals, a cable that moves with the drivetrain or moisture in the plug. The fault often vanishes after a restart and returns under vibration or heat.

Likely causes

Loose or poorly crimped terminal in a Circuit A line
Harness rubbing or flexing at a point that moves with the powertrain
Moisture or contamination in the resolver plug

Symptoms

  • Warning lamp that appears and disappears between trips
  • Brief loss of electric drive or a short jerk
  • Fault often gone after a restart

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time1–5 h

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

Parts involved

drive motor a position sensor awiring harnesshybrid control module

Related codes

P0C50P0C52P0C53P0C5EP0A43

References: gsi.ext.gm.com, law.cornell.edu, en.wikipedia.org.