Powertrain, generic · Hybrid propulsion

P0C53 Drive Motor A Position Sensor Circuit A High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C53 is the high counterpart of P0C52: the reference level on the S1/S3 winding circuit of the motor A resolver rises above its window, typical of a short to a voltage source or an open line that floats up. GM uses an upper limit of 4.5 V on the 2011 Volt, 2013 eAssist and 2016 Volt and ELR, 4.9 V on the 2019 Volt and only 3.0 V on the 2012 two-mode Tahoe, Yukon, Escalade, Sierra and Silverado hybrids. It reacts faster than on the low side: 20 of 30 samples (about 208 ms) on the 2011 Volt, 0.2125 s within 0.3125 s on the 2016 Volt. MIL logic is Type A on the 2011 Volt and the 2012 trucks, Type B on eAssist and the later Volt. No bulletin names this code for motor A.

Likely causes

Open S1 or S3 line or a terminal that has backed out, letting the input drift high
Circuit A line shorted to a voltage-carrying wire in the harness
Broken S1/S3 winding in the resolver stator
Faulty resolver input in the motor control module

Symptoms

  • Check engine lamp with hybrid system message
  • Reduced propulsion or electric drive unavailable
  • Rough engine running on vehicles that use motor A for starting

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time1–6 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

P0C52P0C5DP0C50P0C54P0A42

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.