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.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Camshaft position sensor
- Timing chain
- Timing belt
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Sensor failed
- Timing chain stretched, throwing off sensor timing
- Wiring fault
Possible symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.