P0340 on a Ford: Causes, Fixes & Repair Cost

⚠️ Severe · not recommended to drive

The engine may not start, or it may stall while driving, so have the truck or car towed if it won't start.

What P0340 means on a Ford

On a Ford, P0340 means the engine computer is getting no signal or a bad signal from the camshaft position sensor. Without camshaft position, the computer can't time fuel injection correctly, and the engine may refuse to start or may stall.

Is P0340 common on Fords?

P0340 shows up on Fords with higher mileage, often on F-150, Escape, Focus, and Mustang models with 2.0L and 3.5L EcoBoost or 5.0L engines. The sensor sits at the front of the engine, and sensor failure is the usual cause. Wiring that chafes or corrodes near the front of the engine is also common on these models.

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

Symptoms

Check engine light is on
Engine cranks but won't start
Engine stalls while driving
Rough running or loss of power

Common causes

most common: Failed camshaft position sensor
common: Chafed or corroded wiring to the sensor
common: Loose or damaged sensor connector
less common: Timing chain or timing issues

How to fix it

Fix	DIY?	Typical cost
Replace the camshaft position sensor	Yes	$40–130
Repair chafed or corroded sensor wiring	Mechanic	$100–300
Have a mechanic check the timing chain and guides	Mechanic	$900–1700