Powertrain, generic · Hybrid propulsion

P0C56 Drive Motor B Position Sensor Circuit A Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C56 flags a plausibility problem on Circuit A of the motor B resolver: the winding is connected and its level sits inside the electrical window, yet the signal it carries does not fit, for instance because it wanders or no longer matches the second winding. No manufacturer documents this code publicly. The closest published case is the motor A version P0C51, which Bentley traces to connector pin fit and contamination on its 2025 Continental hybrids. Possible reasons on motor B are the same kind of contact issue, a resolver with weakened output or interference on poorly shielded lines. P0C57 to P0C59 cover hard low, high and sporadic faults, and P0A46 judges the overall motor B angle signal.

Likely causes

Poor pin fit or contamination at the motor B resolver connector
Damaged shield or twisted pair letting interference onto Circuit A
Motor B resolver winding with weakened output

Symptoms

  • Hybrid warning and check engine lamp
  • Motor B torque limited or switched off
  • Occasional shudder when motor B takes load

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1.5–6 h

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

Parts involved

drive motor b position sensor awiring harnesshybrid control module

Related codes

P0C55P0C57P0C58P0C59P0C60P0A46

References: law.cornell.edu, static.nhtsa.gov, en.wikipedia.org.