P0343: Camshaft Position Sensor "A" Circuit High (Bank 1 or Single Sensor)
P0343 means Camshaft Position Sensor "A" Circuit High (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 signal voltage is higher than the maximum the module expects. Typical causes are an open ground circuit, a signal wire shorted to voltage, an unplugged connector, or a failed sensor.
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 P0343
- 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.
Related codes
- P0342 Camshaft Position Sensor "A" Circuit Low (Bank 1 or Single Sensor)
- P0344 Camshaft Position Sensor "A" Circuit Intermittent (Bank 1 or Single Sensor)
- P0341 Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 or Single Sensor)
- P0345 Camshaft Position Sensor "A" Circuit (Bank 2)
- P0340 Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
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.