OBD-II code · Powertrain (generic)

P0A4A Drive Motor B Position Sensor Circuit Overspeed

The drive motor B rotor position sensor reports a circuit overspeed fault. Phase commutation cannot be controlled reliably.

Is it safe to drive with P0A4A?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyRotor position out of expected range
  • PossiblePosition signal lost - default to overspeed indication

Symptoms

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

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
2–8 h
Emissions test
Usually unaffected
Parts involved
Drive Motor B Position Sensor, Wiring Harness, Hybrid Control Module

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.