P0340

OK - a frustrating problem on my 2004 KV6. Saw the error P0340 on my OBDC after doing a thermostat swapout. Accoring to the Rave this is "0340 CMP sensor Open circuit/no signal" it also states that the engine wont start and that there will be a warning light on the dash.... the car starts and the warning light was not displayed.
I then bought and fitted a replacement sensor. The car still starts yet I now get a warning light on the dash (red exclamation mark).
The exact rave quote is "
If the CMP sensor fails during engine running, the engine will run normally until turned off, but will not restart until the CMP sensor input is restored." - it seems to be running fine??
Can anyone tell me what on earth my car is doing?

If the engine is starting, the ECU is getting a cam position signal. If it doesn't see the cam signal, it can't start the engine. This is because it has to initiate the injectors on the correct stroke. It gets this information from the cam sensor.

Once the engine is running, the firing sequence is stored and used until the next start. So if the cam sensor fails while running. The engine will continue to run as if nothing is amiss. The MIL might light in this instance, but not always.

So how can it start if i'm getting that error? The car starts every time and seems to be running fine?

Liam Deeney said:

So how can it start if i'm getting that error? The car starts every time and seems to be running fine?

Click to expand...

That I'm not sure of. Is the wiring to the sensor sound. There are a couple of connections in that circuit.

I'll have a dig. I did take a lot off the top when i replaced the thermostat. Ergh.

Leason learnt. Don't work at night tired. Had another look today in daylight. The old rubber o-ring was stuck in the manifold. Didn't see it as it was blackened. Took it out, refitted the new sensor, error gone and car starts instantly again.