P0EF3Drive Motor C Temperature Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0EF3 is stored when the signal voltage of the drive motor C temperature sensor drops below its valid range. With the usual NTC thermistor on a pull-up resistor, a low voltage stands for an extremely hot winding, so electrically the suspects are a short to ground, a pinched harness or a sensor with an internal short. No manufacturer documents P0EF3 publicly. GM's motor B table for the 2016 Cadillac ELR shows the analogous limit: P0A32 trips once the reading corresponds to more than 184 °C, close to 0 V, after a 90 s warm-up, Type A. Ford's 2019 hybrids fail the motor coil sensor below 0.1 V held for 32 ms. Because the controller cannot tell such a short from real overheating, it derates motor C. P0EF4 covers the high-voltage side.
- What you may notice
- Drive power of motor C reduced immediately
- Implausibly high motor temperature in the live data
- Warning lamp on
- Likely causes
- LikelySignal wire shorted to ground or motor housing
- PossibleThermistor shorted internally
- PossibleWater or coolant in the connector bridging the pins
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.