OBD-II code · Powertrain (generic)
P0340 Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
The camshaft position (CMP) sensor signal is missing or implausible. The ECU uses CMP together with CKP to identify cylinder phase for sequential injection and coil-on-plug ignition; without CMP the engine may run on group injection or fail to start.
Is it safe to drive with P0340?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor failed
- PossibleTiming chain stretched, throwing off sensor timing
- Less likelyWiring fault
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Camshaft Position Sensor, Timing Chain, Timing Belt
Related codes
- P033DKnock/Combustion Vibration Sensor D Circuit High
- P033EKnock/Combustion Vibration Sensor D Circuit Intermittent
- P033FCrankshaft/Camshaft Loss Of Synchronization
- P0341Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1)
- P0342Camshaft Position Sensor "A" Circuit Low Input (Bank 1)
- P0343Camshaft Position Sensor "A" Circuit High Input (Bank 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.