What it means
The control module detected a range or performance fault in the drive motor A coolant temperature sensor circuit. The reading may be unreliable; the resulting vehicle response depends on the vehicle.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The drive motor A coolant temperature sensor tracks coolant temperature so the control module can manage and protect that motor. This code sets when the sensor circuit’s reading is outside the expected range or responds implausibly over time, which can indicate sensor drift, aging, or incorrect sensor mounting.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Save freeze-frame data and compare drive motor A coolant temperature with ambient temperature and other available temperature readings.
- Monitor motor A coolant temperature from a cold start to see whether it rises plausibly or stays offset, lags, or jumps unexpectedly.
- With the vehicle powered down, inspect the sensor’s mounting and connector for displacement, looseness, corrosion, or harness damage.
- Check the motor A sensor wiring for opens or shorts and inspect the cooling circuit for leaks that could affect the reading.
- Test the drive motor A coolant temperature sensor against the manufacturer’s specification and replace it if its response is outside range.
Common fixes
- Secure the drive motor A coolant temperature sensor in its intended mounting position.
- Clean or repair a loose or corroded connector and damaged motor A sensor wiring.
- Replace the sensor if its temperature response fails the manufacturer’s specification.
- Repair any confirmed coolant leak in the drive motor A cooling circuit.
Can I keep driving?
A range or response fault can cause the vehicle to limit motor A power because its cooling temperature is uncertain. Avoid hard acceleration and extended trips if reduced power is present, and stop safely if an overheating warning or shutdown occurs.
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.