Powertrain, generic · Hybrid propulsion

P0A6C Drive Motor B Phase W Current

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A6C covers a general fault in the phase W current of drive motor B. No manufacturer documents P0A6C publicly. Where motor B sits on a separate axle, its three high-voltage phase leads are long and exposed, so cable and terminal faults are a realistic cause; for the motor A phase codes P0A5D, P0A60 and P0A63, Audi blames welding variances in the high-voltage wiring of the 2021-23 Q5 e quattro. On the sensing side, a Caterpillar patent recognises a dead phase sensor by its near-zero reading combined with a violated zero-sum of the three currents. CARB requires circuit and plausibility checks of drive components. P0A6D and P0A6E are the low and high cases, P0A66 and P0A69 phases U and V, P0A63 motor A. Motor B is switched off.

Likely causes

Phase W high-voltage lead or terminal to motor B damaged or loose
Phase W current sensor failed
Internal fault of the motor B inverter

Symptoms

  • Hybrid warning lamp and MIL
  • Loss of electric drive on the axle driven by motor B

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–6,000
Time1.5–8 h

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

Parts involved

drive motor b phase winverter

Related codes

P0A6DP0A6EP0A66P0A69P0A63

References: patents.google.com, static.nhtsa.gov, law.cornell.edu.