Powertrain, generic · Hybrid propulsion

P0A6D Drive Motor B Phase W Current Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A6D completes GM's set of open-phase tests for drive motor B with phase W. Because each phase is only judged while the rotor sits within 30 degrees of its own axis, the code points to W alone rather than to the motor as a whole. GM's tables for the 2016 Volt require a running drive, more than 50 V on the inverter in normal PWM and a squared current command above 900 A²; the 2018 tables for Volt and CT6 use 4,900 A². If the W peak stays under 9 A for 0.4 s within 0.6 s, the Type A fault turns on the MIL after one trip. Typical findings are an interrupted W lead or terminal, a non-conducting switch or a sensor reading zero. P0A6E is the high side, P0A67 and P0A6A phases U and V, P0A64 the motor A test.

Likely causes

Phase W lead or terminal of motor B interrupted
Phase W switch of the inverter not conducting
Phase W current sensor stuck at zero
Open phase W winding in motor B

Symptoms

  • MIL on the first trip with propulsion warning
  • Rough or reduced electric drive

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

P0A6CP0A6EP0A67P0A6AP0A64

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