P0EF4 code meaning
Drive Motor C Temperature Sensor Circuit High
Powertrain system Generic code P0Exx codes Check engine light
What P0EF4 means
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.
P0EF4 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0EF4
- Reduced power of motor C
- Motor temperature stuck at the lowest value in the live data
- Warning lamp on
Common causes of P0EF4
- Most likelySensor connector unplugged, loose or with pushed-back pin
- PossibleBroken signal or ground wire of the sensor
- PossibleThermistor open internally
- Less likelySignal wire shorted to the 5 V reference
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor c temp sensorWiring harnessHybrid control module
What each part of P0EF4 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| F4 | The exact fault in that area. |
What to do next
- Note P0EF4 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0EF4
What does P0EF4 mean?
P0EF4 means "Drive Motor C Temperature Sensor Circuit High". P0EF4 reports a drive motor C temperature signal above the plausible window. It is a generic code, so it means the same on every make.
Is it safe to drive with P0EF4?
Drive gently and only to a workshop. With P0EF4 the car can go into limp mode (reduced power) to protect itself.
Will P0EF4 fail an emissions test?
Yes, it can. P0EF4 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0EF4 to fix?
Difficulty: hard. A typical repair takes 0.5 to 6 hours of work. This is a job for a workshop.
Will P0EF4 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.