P0340 on a Honda: Causes, Fixes & Repair Cost

⚠️ Severe · not recommended to drive

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

What P0340 means on a Honda

On a Honda, 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 Hondas?

P0340 shows up on Hondas with higher mileage, often on Civic, Accord, CR-V, and Pilot models with 1.5L turbo, 2.0L, and 2.4L engines. The sensor sits near the valve cover, and sensor failure is the usual cause. Oil leaks that soak the connector are a common trigger too.

Commonly reported on: Civic, Accord, CR-V, Pilot.

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: Oil-soaked or corroded connector from a valve cover leak
common: Damaged wiring to the sensor
rare: Timing chain or timing issues

How to fix it

Fix	DIY?	Typical cost
Replace the camshaft position sensor	Yes	$40–120
Replace the valve cover gasket if oil is leaking onto the sensor	Mechanic	$100–300
Repair damaged sensor wiring or connector	Mechanic	$100–250