A loose, corroded, or damaged electrical connector at the drive motor C temperature sensor.; Chafed, pinched, or broken wiring in the sensor circuit harness, often near moving components or heat sources.; A failing temperature sensor itself, where internal components become intermittent with temperature or vibration.; Poor terminal tension or water intrusion at the sensor pigtail or inline connectors.; Electrical interference from nearby high-voltage cables or improper shielding causing signal noise.; A faulty powertrain control module or interface module, though this is the least likely cause.

DTC codes / P0Exx · Hybrid propulsion / P0EF6

P0EF6Drive Motor C Temperature Sensor Circuit Intermittent/Erratic

P0EF6 indicates that the powertrain control module has detected an intermittent or erratic signal from the temperature sensor circuit of drive motor C, which is the third traction motor in a multi-motor hybrid or electric vehicle. The computer sets this code when the sensor's voltage or resistance readings jump unpredictably rather than failing completely, making the motor's temperature data unreliable for protection and performance strategies.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message, often with no other noticeable symptoms.
Intermittent power reduction or limp mode triggered by the control module when temperature readings become erratic.
Unusual hybrid system warnings or shutdown of the affected drive motor under load.
Fluctuating or inaccurate temperature readings on a scan tool data stream for drive motor C.
In rare cases, overheating of the motor if the erratic signal prevents proper cooling fan or power derating.

Common causes, most likely first

A loose, corroded, or damaged electrical connector at the drive motor C temperature sensor.
Chafed, pinched, or broken wiring in the sensor circuit harness, often near moving components or heat sources.
A failing temperature sensor itself, where internal components become intermittent with temperature or vibration.
Poor terminal tension or water intrusion at the sensor pigtail or inline connectors.
Electrical interference from nearby high-voltage cables or improper shielding causing signal noise.
A faulty powertrain control module or interface module, though this is the least likely cause.

How to diagnose and fix it

Inspect the drive motor C temperature sensor connector and harness for looseness, corrosion, or physical damage, and clean or repair as needed.
Perform a wiggle test on the sensor wiring while watching live temperature data on a scan tool to reproduce the intermittent signal.
Measure the sensor's resistance or voltage at the sensor and at the control module, comparing readings to specifications to isolate a wiring or sensor fault.
Check for continuity and short-to-ground or short-to-power on each wire in the sensor circuit, repairing any damaged sections.
Replace the drive motor C temperature sensor if the wiring and connectors prove good but the signal remains erratic.
Clear the diagnostic trouble codes and verify the repair by test-driving the vehicle under conditions that previously set the code.
If the code persists after all circuit and sensor checks, follow the manufacturer's diagnostic flow for control module testing or reprogramming.

Intermittent sensor faults that fool technicians

A temperature sensor that tests perfectly at room temperature can still be intermittent when the motor heats up, so resistance checks must be repeated at operating temperature.
The code often sets only during specific driving conditions such as high-load acceleration or after a cold start, making a simple idle test insufficient for confirmation.
Water intrusion into the sensor connector is a frequent hidden cause, especially on vehicles that have been driven through deep water or in heavy road spray.
Technicians sometimes replace the sensor only to find the real fault is a chafed wire inside a harness loom that only shorts when the motor mounts flex under torque.
This code does not always mean the sensor is failing; a poor ground connection shared with other sensors can create erratic readings that mimic a sensor fault.

Can I keep driving with P0EF6?

You can usually continue driving if the only symptom is the warning light, but avoid heavy acceleration or sustained high-load driving until the fault is repaired. If the vehicle enters limp mode or shows overheating warnings, stop driving and have it diagnosed promptly to prevent motor damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.