Drive with caution — fix soon.
P0340 indicates a problem with the camshaft position sensor circuit. This sensor helps the computer track valve timing and coordinate fuel injection and spark. Causes are usually a failed sensor, wiring or connector issues, and it can lead to starting and drivability problems.
$150 – $550
Varies by vehicle and root cause.
Sometimes, but it's a gamble. A failing cam sensor can cause stalling or a no-start without warning, so get it checked promptly.
Typically $150 to $550, depending on the sensor's location and how much labor is needed to reach it.
It's moderate. The car may run, but the risk of stalling or hard starts means you shouldn't leave it unrepaired for long.
The crankshaft sensor tracks the crank's rotation, while the camshaft sensor tracks valve timing; the computer uses both to time the engine correctly.