P0117 on a Chevy: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Safe to drive for a short time, but the engine may run rich and burn extra fuel, and the cooling fan may run constantly.

What P0117 means on a Chevy

On a Chevy, P0117 means the engine coolant temperature (ECT) sensor is reading very hot because the signal voltage is too low. The usual causes are a failed sensor, a shorted wire, or a corroded connector. The computer may run the engine rich and keep the cooling fan running.

Is P0117 common on Chevys?

Silverados, Malibus, and Equinoxes commonly see P0117 with age, usually from the sensor failing or wiring damage. GM ECT sensors are inexpensive and the repair is straightforward, so this is usually a low-cost fix.

Commonly reported on: Silverado, Malibu, Equinox, Tahoe.

Symptoms

Check engine light on
Cooling fan runs constantly
Poor fuel economy from rich running
Hard starting when the engine is cold

Common causes

most common: Faulty coolant temperature sensor
common: Sensor wiring shorted to ground
common: Corroded or loose connector terminals
less common: Damaged wiring near the sensor

How to fix it

Fix	DIY?	Typical cost
Replace the coolant temperature sensor	Yes	$15–45
Repair the wiring or connector	Mechanic	$50–150
Have a shop replace the sensor and verify the circuit	Mechanic	$100–200