P0EF6 is not an electrical fault: the drive motor C temperature sensor delivers a believable value, but that value has passed the motor's protection limit. No manufacturer documents P0EF6 publicly. For motor B on the 2016 Cadillac ELR, GM sets P0A35 when the temperature exceeds 149 °C and does not fall back below a reset threshold, Type A, and only while the range check P0A31 is passing. Ford's 2019 hybrids set P0A2F at a coil temperature above 140 °C or transmission oil above 115 °C. Causes are mostly on the cooling side, such as low coolant or oil, a failed pump or a clogged cooler, but long full-load phases or a winding with shorted turns also heat the motor. Torque of motor C is cut until it cools; sensor circuit faults belong to P0EF1 to P0EF5.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Clearly reduced power until the motor has cooled down
- Warning about drive system overheating
- MIL on (manufacturer-dependent)
Most likely causes
- Low coolant or oil level, or air in the motor cooling circuit
- Failed coolant or oil pump, or clogged cooler
- Long full-load phases such as towing, track use or steep climbs
- Shorted turns in the stator winding generating extra heat
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
- It affects emissions.
What each character of P0EF6 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- E: Subsystem depends on the code range
- F6: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0EF6?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0EF6?
The most common causes are: low coolant or oil level, or air in the motor cooling circuit; failed coolant or oil pump, or clogged cooler; long full-load phases such as towing, track use or steep climbs.
Related codes
- P0A35Drive Motor B Over Temperature
- P0A2FDrive Motor A Over Temperature
- P0EF1Drive Motor C Temperature Sensor Circuit
- P0EF2Drive Motor C Temperature Sensor Range/Performance
- P0EEFDrive Motor A Control Module Overtemperature
Sources
- gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
- fordservicecontent.com: OBDSM1901 HEV
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.