P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
P0340 means Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor). The camshaft position (CMP) sensor on bank 1 (the side with cylinder 1) tells the engine computer the camshaft's position, which identifies which cylinder is on its compression stroke. The control module has detected a fault in the circuit itself, such as an open circuit, a short, or a signal outside the electrical limits it expects.
Can I keep driving? Limit driving and diagnose promptly. Continued driving can cause damage, stalling or limp mode.
Common symptoms
- Check engine light on
- Long cranking or hard starting
- Rough running or stalling
- Reduced power
Possible causes
- Failed camshaft position sensor
- Wiring or connector fault
- Damaged camshaft reluctor
- Oil in the connector from a leaking seal
- Timing chain or belt that has jumped
How to diagnose P0340
- Inspect the connector and wiring.
- Check sensor power, ground and signal.
- Check whether cam/crank correlation codes are also present.
- Inspect the reluctor and mechanical timing if the sensor checks out.
What the code means, digit by digit
Generic codes have the same definition on every OBD-II vehicle (petrol cars from model year 1996 in the US, 2001 in the EU; diesels later). Manufacturers can add their own enhanced codes; those are not listed here.
Symptoms linked to P0340
Related codes
- P0341 Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 or Single Sensor)
- P0342 Camshaft Position Sensor "A" Circuit Low (Bank 1 or Single Sensor)
- P0343 Camshaft Position Sensor "A" Circuit High (Bank 1 or Single Sensor)
- P0344 Camshaft Position Sensor "A" Circuit Intermittent (Bank 1 or Single Sensor)
- P0345 Camshaft Position Sensor "A" Circuit (Bank 2)
General guidance only. Fault codes describe what the engine computer saw, not which part failed: confirm with testing before replacing parts, and follow the vehicle's service information.