What does it mean?
P1340 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Crankshaft Position/Camshaft Sensor Signal Out of Sequence .
Symptoms
- Rattle from the timing area for a few seconds at cold start
- Rough running, misfire and noticeable loss of power
- Hard starting, and in severe cases the engine cranks but does not fire
- Check engine light on, frequently with misfire and variable valve timing codes
- Higher fuel consumption and poor throttle response
Likely causes
- Stretched timing chain or a belt that has jumped a tooth, shifting cam timing relative to the crank
- Worn chain guides, a weak tensioner or a tensioner that bleeds down when the engine is off
- Cam phaser unable to hold its position because of low oil level, degraded oil or a clogged oil control valve screen
- Loose or sheared reluctor wheel key on the crank or cam, letting the trigger wheel move
- Assembly error after timing work, with the marks aligned one tooth out
- Intermittent or noisy signal from the crank or cam sensor, or induced noise from a damaged shield
- Failed variable valve timing actuator locking pin, which lets the cam wander at start-up
How to fix it
- Read all codes and freeze frames; if the fault set at start-up, focus on chain slack and phaser lock rather than sensors
- Check engine oil level and condition, since low or sludged oil is a very common trigger for cam timing errors
- Compare the cam and crank signals on a scope to see whether the relationship shifts or the pulses are simply noisy
- Inspect both sensors and their harnesses for damage, then check the reluctor wheels for movement or damage
- Use the manufacturer's cam timing check procedure or a phaser position reading in live data to measure the actual offset
- Verify the timing chain or belt condition, tensioner extension and guide wear before ordering parts
- Correct the mechanical timing, replace worn chain hardware or a failed phaser as required, then clear the code and confirm the correlation stays within range