P0A18: Motor Torque Sensor Circuit Range/Performance

What it means

The drive motor torque sensor reports a circuit range/performance fault. Motor torque feedback is unreliable.

At a glance

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

How it works

The motor torque sensor reports drive motor torque to the hybrid control system. This code sets when the signal is outside the expected range or does not track torque as expected, even if the circuit is not simply open or shorted; a worn sensor or wiring fault can cause that mismatch.

Common causes

Most likely first.

1. Torque sensor failed
2. Wiring fault
3. Sensor element aged beyond calibration window

Symptoms

• Hybrid system or check-engine warning light on
• Reduced hybrid power or acceleration
• Possible rough or inconsistent power delivery

How to diagnose it

1. Record freeze-frame data and compare torque-sensor live data with commanded motor torque during the conditions that set the code.
2. Check for related hybrid-system codes and determine whether the signal is erratic, offset, or only out of range under certain conditions.
3. Inspect the torque-sensor connector and harness for looseness, corrosion, chafing, or strain that could distort the signal.
4. Check the sensor circuit connections and wiring against the vehicle diagram and manufacturer's test procedure.
5. Test sensor response across its operating range to the manufacturer's specification to identify a failed or aged sensor.

Common fixes

• Secure the torque-sensor connector and repair poor or damaged connections.
• Repair wiring damage affecting the torque-sensor signal.
• Replace the torque sensor if its output falls outside the specified operating range.

Can I keep driving?

The hybrid system may limit power, and acceleration can become uneven, so avoid fast traffic and hard acceleration until diagnosed. Stop safely if power drops significantly or the vehicle will not remain in READY.