P0EF4Drive Motor C Temperature Sensor Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0EF4 reports a drive motor C temperature signal above the plausible window. For an NTC sensor on a pull-up this equals an impossibly cold winding, the picture produced by an open sensor, a broken wire, an unplugged connector or a short to the reference voltage. No manufacturer documents P0EF4 publicly. GM's ELR motor controller treats the same situation for motor B as P0A33 once the value reads below −41 °C, near 5 V, while Ford flags the coil sensor of its 2019 hybrids once the voltage exceeds 4.8 V for 32 ms. A sensor that claims far too low a temperature would hide real overheating, so the controller switches to a substitute value and limits the output of motor C. Check the connector at the motor first; the low-side sibling is P0EF3.
- What you may notice
- Reduced power of motor C
- Motor temperature stuck at the lowest value in the live data
- Warning lamp on
- Likely causes
- LikelySensor connector unplugged, loose or with pushed-back pin
- PossibleBroken signal or ground wire of the sensor
- PossibleThermistor open internally
- RareSignal wire shorted to the 5 V reference
- 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.