P0118 on a Volvo: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Safe to drive, but the engine may run rich and use more fuel until the sensor circuit is repaired.

What P0118 means on a Volvo

On a Volvo, P0118 means the engine coolant temperature (ECT) sensor is sending a high-voltage signal that the computer reads as the engine being very cold. The sensor is typically mounted near the thermostat or in the engine block, and an open circuit from a failed sensor or broken wire is the usual cause. The computer then enriches the fuel mixture as if the engine were cold.

Is P0118 common on Volvos?

P0118 appears on higher-mileage S60, XC60, and XC90 models. Aging wiring and connectors that corrode after years of heat and moisture are common contributors on Volvos, so inspect the connector before replacing parts.

Commonly reported on: S60, XC60, XC90, V60.

Symptoms

Check engine light on
Poor fuel economy
Hard cold start
Engine runs rich

Common causes

most common: Faulty coolant temperature sensor
common: Open sensor signal wire
common: Corroded connector
less common: Wiring damaged by heat

How to fix it

Fix	DIY?	Typical cost
Replace the coolant temperature sensor	Yes	$30–80
Repair the sensor wiring or connector	Mechanic	$80–200
Have a shop diagnose the circuit	Mechanic	$100–150