Powertrain, generic (extended)

P2C71 Drive Motor A Phase Z Current High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C71 reports overcurrent in phase Z of drive motor A, the last phase of the second winding set. No manufacturer documents P2C71 publicly. Once overcurrent is detected the inverter has to bring the machine into a safe state, and the Mitsubishi Electric patent on dual-winding drives deals with exactly that: when the battery link opens, each winding set is moved in steps from a phase short circuit to all switches off, at different times, so that the voltage induced by the spinning rotor cannot damage the inverter. For the driver this means a sudden loss of drive power and a warning. Ford's limits for the U/V/W case, 600 A for 400 microseconds, show how fast such checks are. Suspect a shorted switch, a winding or lead short, or a sensor error. P2C70 is the low side, P2C6B and P2C6E are X and Y.

Likely causes

Shorted power semiconductor in the Z leg
Short in the phase Z winding or lead, to another phase or ground
Phase Z current sensor reading too high or noisy
Inverter control software reacting wrongly to transients

Symptoms

  • Sudden loss of drive power with hybrid or drive warning
  • MIL on, vehicle may not restart into ready mode

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€400–7,000
Time1.5–8 h

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

Parts involved

drive motor adrive motor a phase zinverter

Related codes

P2C6FP2C70P2C6BP2C6EP0A65P0A78

References: patents.google.com, fordservicecontent.com, law.cornell.edu.