Powertrain, generic · Hybrid propulsion

P0A6A Drive Motor B Phase V Current Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A6A is GM's open-circuit test for phase V of drive motor B. The controller checks each phase on its own as the rotor turns; for phase V it looks at the window of 30 degrees either side of the V axis, where the current should be largest. With the inverter above 50 V in normal PWM and a squared current command above 900 A² (2016 Volt) or 4,900 A² (2018 and 2019 tables), a peak below 9 A for 0.4 s out of 0.6 s is a Type A failure with MIL after one trip. The 2016 Volt table describes this motor B code with the words drive motor A, an evident copy slip. A missing V current points to a broken lead, a dead switch or a sensor stuck at zero. P0A6B is the high side, P0A67 and P0A6D phases U and W, P0A61 the motor A code.

Likely causes

Phase V lead, connector or bolted terminal of motor B open
Phase V switch of the motor B inverter not switching
Phase V current sensor output stuck at zero
Open phase V winding in motor B

Symptoms

  • MIL and propulsion system warning after the first trip
  • Vibration or uneven torque from motor B before shutdown

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 vinverter

Related codes

P0A69P0A6BP0A67P0A6DP0A61

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