P0118 on a Ford: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Safe to drive, but the engine may run rich and struggle to start in cold weather until the sensor circuit is repaired.

What P0118 means on a Ford

On a Ford, 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 threads into the engine block or thermostat housing, and an open circuit from a failed sensor or broken wire is the typical cause. The computer then adds extra fuel as if the engine were always cold.

Is P0118 common on Fords?

P0118 is common on higher-mileage F-150, Focus, and Escape models. Corroded connector terminals are a known trouble spot on Ford engines, and sensor failures become more common as the vehicles age.

Commonly reported on: F-150, Focus, Escape, Explorer.

Symptoms

Check engine light on
Poor fuel economy
Hard starting in cold weather
Engine runs rich

Common causes

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

How to fix it

Fix	DIY?	Typical cost
Replace the coolant temperature sensor	Yes	$20–60
Repair the sensor wiring or connector	Mechanic	$50–150
Have a shop diagnose the circuit	Mechanic	$80–120

Frequently asked questions

Can I drive my Ford with a P0118 code?

Yes. The engine will run rich and use more fuel, but it is not an emergency. Fix the circuit soon so cold starts and fuel economy improve.

Why does P0118 happen on Fords?

A failed coolant temperature sensor is the most common cause, with corroded connector terminals and broken wires close behind on higher-mileage trucks and SUVs.

How much does it cost to fix P0118 on a Ford?

A replacement sensor is about $20 to $60, plus labor if a shop does it. Wiring repairs run about $50 to $150.