P0A48

What it means

P0A48 means the hybrid or electric drive control unit has seen the signal from the Drive Motor 'B' position sensor (usually a resolver or encoder) read higher than its allowed range. The control unit needs this signal to know the exact rotor angle so it can time the motor current correctly. A high-voltage reading usually points to a short to voltage, an open circuit that lets the signal float high, or a faulty sensor. Layout and the motor designated 'B' vary by model, so confirm which motor it is for the vehicle.

Symptoms

• Hybrid or powertrain warning light on
• Reduced power or limp mode
• Reduced or no electric drive assistance or regenerative braking
• Rough running or judder when the motor engages
• Engine runs more than normal on a hybrid, or the vehicle will not enter Ready mode

Possible causes

• Damaged, chafed or corroded wiring or connector in the motor position sensor circuit (short to voltage or open circuit)likely
• Faulty drive motor position sensor (resolver or encoder)likely
• Poor connection or water ingress at the motor or inverter connectorpossible
• Sensor reference or supply voltage fault, or signal wire shorted to another powered circuitpossible
• Fault in the inverter or motor control unitrare
• Mechanical damage or misalignment of the sensor or rotor position reference after motor or transmission workrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting any other motor, inverter or hybrid system codes.
2. Check for relevant technical service bulletins and the manufacturer's wiring diagram to identify which motor is 'B' and the sensor circuit layout for this model.
3. Visually inspect the motor position sensor wiring and connectors for chafing, heat damage, corrosion, moisture and bent or pushed-back pins. Only a technician trained in high-voltage systems should work around the hybrid or EV system, following the proper isolation procedure.
4. Wiggle-test the harness with live data on display to see if the sensor signal or fault status changes.
5. With the system safely isolated, check the sensor circuit wiring for continuity, short to voltage and short to earth, against the specified values.
6. Check the sensor supply and signal values with a suitable meter or scope, and compare the sensor coil resistance with the manufacturer's specification.
7. If wiring and sensor test fine, check the inverter or motor control unit connectors, and check for software updates before considering the control unit itself.
8. Clear the code and road test, confirming it does not return and the live data stays in range.

How to fix

• Repair or replace damaged wiring and connectors in the position sensor circuit, and seal against moisture.
• Replace the drive motor position sensor or resolver if it fails testing, following the manufacturer's procedure and any alignment or learning steps required.
• Clean or replace corroded or loose terminals and renew damaged connector seals.
• Correct any short to voltage found between the signal circuit and other powered wiring.
• Replace or reprogram the inverter or control unit only after confirming a fault with it, or if an applicable calibration update addresses this code.

Can I keep driving?

Nearby codes

• P0A47GenericDrive Motor B Position Sensor Circuit Low
• P0A49GenericDrive Motor B Position Sensor Circuit Intermittent