OBD-II fault code

P0A6B: Drive Motor B Phase V Current High

What it means

Drive motor B phase V current is above the expected range. The code identifies a high-current condition but does not establish its cause.

At a glance

  • Usually lights the check-engine light
  • The engine or gearbox may go into limp mode

How it works

The inverter switches current through drive motor B’s phase V winding to create torque. The module monitors phase V current and sets this code when the measured current is above the expected range; a short between phases or a stalled rotor can produce that high current.

Common causes

Most likely first.

  1. Short between motor phases
  2. Rotor stalled - high stall current

Symptoms

  • EV/hybrid system warning light on
  • Reduced motor power or torque
  • Possible limp mode or vehicle shutdown

How to diagnose it

  1. Save freeze-frame data and compare live motor B phase V current with phases U and W, looking for an unusually high or unbalanced reading.
  2. Review related motor B, inverter, and rotor-speed codes for indications of a phase short or stalled motor.
  3. With the vehicle safely powered down according to the manufacturer’s procedure, inspect motor B phase wiring for damaged insulation, melted areas, or phase conductors touching.
  4. Have the motor B windings and insulation tested for a phase-to-phase short using the manufacturer’s procedure.
  5. If the wiring and motor pass, have the rotor and inverter checked for a stall or a fault that could cause excessive phase V current.

Common fixes

  • Repair chafed or damaged phase wiring and restore insulation between conductors.
  • Repair a damaged motor B phase V connector.
  • Repair or replace the motor if a phase-to-phase short or rotor seizure is confirmed.
  • Repair or replace the inverter if testing confirms it is driving phase V current too high.

Can I keep driving?

Do not continue driving if torque is reduced, the motor makes abnormal noise, limp mode activates, or a shutdown warning appears; propulsion may fail and high current can damage the motor or inverter. Arrange prompt diagnosis.

A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together

This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.

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