P0A6A

What it means

P0A6A is a generic hybrid or electric vehicle code meaning the control unit has seen the phase V current for drive motor B reading lower than expected. This usually comes from the motor phase current sensor or its circuit, or from the inverter and motor winding. The exact trigger thresholds and the sensor layout depend on the make and model.

Symptoms

• Hybrid or EV system warning light, or a malfunction indicator lamp, on the dashboard
• Reduced power or limp mode
• Jerky, weak or uneven acceleration
• Vehicle will not enter READY mode, or shuts down while driving
• Poor efficiency, or the engine running more than usual on a hybrid

Possible causes

• Faulty phase V current sensor, or a sensor reading that has drifted out of rangelikely
• Wiring or connector fault in the phase V current sensor circuit (open circuit, high resistance, corrosion, chafing)likely
• Fault inside the inverter or motor control modulepossible
• Loose, corroded or damaged high-voltage phase cable or connection between the inverter and drive motor Bpossible
• Open or damaged winding in drive motor Brare
• Low or unstable supply voltage or a poor earth to the inverter or motor control unitrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting speed, load, temperature and system voltage when the fault set. Check for other drive motor or inverter codes.
2. Check for relevant technical service information and software updates for the model and motor layout.
3. Carry out a visual inspection of the wiring and connectors for the motor current sensors and inverter, looking for damage, water ingress, corrosion and loose fit.
4. Check the 12 V battery condition and the supply and earth connections to the inverter or motor control unit, as low voltage can cause false readings.
5. Using a scan tool, compare the phase U, V and W current readings with the system at rest and under load. A phase V reading that differs from the others points to the sensor or circuit.
6. Have a trained high-voltage technician isolate the system following the manufacturer's procedure before touching any orange cabling, then inspect the phase cable connections.
7. With the high-voltage system safely isolated, test the sensor circuit continuity and the motor winding resistance and insulation against the manufacturer's specification.
8. Clear the code after repair and road test to confirm it does not return.

How to fix

• Repair or replace damaged wiring, terminals or connectors in the phase V current sensor circuit.
• Replace the phase V current sensor, or the inverter assembly if the sensor is not serviced separately.
• Repair or replace the inverter or motor control unit if it is confirmed faulty, and carry out any required programming or setup.
• Clean, refit and tighten the high-voltage phase connections to the manufacturer's torque, or replace damaged phase cables.
• Replace or repair drive motor B if the winding is found to be faulty.
• Correct any low 12 V supply or earth fault, and apply any available manufacturer software update if it is a known cause.

Can I keep driving?

Nearby codes

• P0A69GenericDrive Motor B Phase V Current
• P0A6BGenericDrive Motor B Phase V Current High