Damaged or chafed wiring in the phase W cable between the inverter and motor B; Loose or corroded terminal at the motor B phase W connector or inverter connector; Internal short or open circuit in the motor B stator winding for phase W; Failed current sensor inside the inverter or motor control unit; Faulty inverter power module affecting phase W current output; Moisture intrusion into the phase W connector or motor housing causing intermittent current leakage

DTC codes / P0Axx · Hybrid propulsion / P0A6C

P0A6CDrive Motor B Phase W Current

Q: What does code P0A6C mean?

Drive Motor B Phase W Current. P0A6C indicates that the hybrid or electric vehicle's motor control unit has detected an abnormal current condition in phase W of the three-phase drive motor B circuit. The computer compares commanded current with actual feedback and flags this code when the measured current in that phase deviates from the expected value beyond a calibrated threshold.

P0A6C indicates that the hybrid or electric vehicle's motor control unit has detected an abnormal current condition in phase W of the three-phase drive motor B circuit. The computer compares commanded current with actual feedback and flags this code when the measured current in that phase deviates from the expected value beyond a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the hybrid system warning light or service vehicle soon message
Reduced power output or limp-home mode with limited vehicle speed
The vehicle may refuse to start or shift into drive if the fault is active at key-on
Possible shuddering or rough operation during acceleration if the motor is still partially functional
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Damaged or chafed wiring in the phase W cable between the inverter and motor B
Loose or corroded terminal at the motor B phase W connector or inverter connector
Internal short or open circuit in the motor B stator winding for phase W
Failed current sensor inside the inverter or motor control unit
Faulty inverter power module affecting phase W current output
Moisture intrusion into the phase W connector or motor housing causing intermittent current leakage

How to diagnose and fix it

Perform a visual inspection of the phase W cable and connectors for chafing, corrosion, or loose pins
Measure the resistance of the phase W winding and compare it to the other two phases to check for an open or short
Use a scan tool to monitor live current feedback for phase W while gently wiggling the harness to reveal intermittent faults
Check for technical service bulletins or software updates for the motor control unit that address current-sensing calibration
Perform an insulation resistance test on the phase W cable and motor winding to rule out a ground fault
If wiring and motor check out, substitute a known-good inverter or motor control unit to isolate the fault
Clear the code and perform a road test to confirm the repair, then verify no pending codes return

Phase W current faults that fool technicians

A loose ground connection for the motor or inverter can cause phantom phase current faults because the current sensor reference shifts, so always verify ground integrity before condemning the motor.
Intermittent P0A6C codes often appear after a car wash or heavy rain when moisture enters the phase W connector, and the code may not reset until the connector is dried and resealed.
The code can be set by a failing 12-volt auxiliary battery that causes voltage drops during cranking, which corrupts the current sensor readings at key-on.
Technicians sometimes replace the motor when the real fault is a chafed phase W cable rubbing against a bracket, so a thorough harness inspection with a mirror is essential.
After any repair involving the phase W circuit, the motor control unit may need a calibration or learn procedure to relearn the current offset, otherwise the code can return immediately.

Can I keep driving with P0A6C?

Do not continue driving with an active P0A6C code because a phase current fault can lead to sudden loss of motive power or further damage to the inverter and motor. Have the vehicle towed to a qualified hybrid service facility for diagnosis.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.