P0117 on a Volkswagen: 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 Volkswagen

On a Volkswagen, P0117 means the engine coolant temperature sensor is reading very hot because the signal voltage is too low. VW coolant sensors are known to fail with age, and a shorted wire or failed sensor is the usual cause. The computer may run the engine rich and keep the fan on.

Is P0117 common on Volkswagens?

Jettas, Golfs, and Passats commonly see P0117 when the coolant temperature sensor fails. On many VW engines the sensor sits in a coolant flange that can also leak, so the repair often includes the flange along with the sensor.

Commonly reported on: Jetta, Golf, Passat, Tiguan.

Symptoms

Check engine light on
Cooling fan runs constantly
Poor fuel economy from rich running
Coolant leak near the sensor flange

Common causes

most common: Faulty coolant temperature sensor
common: Sensor wiring shorted to ground
common: Leaking or cracked coolant flange
less common: Corroded or loose connector terminals

How to fix it

Fix	DIY?	Typical cost
Replace the coolant temperature sensor	Yes	$20–50
Replace the sensor and coolant flange together	Yes	$40–100
Have a shop replace the sensor and check for leaks	Mechanic	$140–280