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MG MGF Technical - camshaft sensor malfunction

I have a fault stored in the ECU -

Camshaft Position Sensor A- Bank 1 Circuit Malfunction

Can anyone enlighten me as to what this means?

Should i just replace with a new sensor or is it more of an elctrical thing upstream/downstream?

Thanks

I Brown

Is this a recurrent fault - and how is the engine running at the moment?

The camshaft position sensor essentially takes over the role of the distributor in timing the spark firing order (it's a wasted spark system, so the plugs fire in pairs anyway).
Rob Bell

How old is your car Ian ?

The early VVCs had an external twin coil pack later had coils built into the spark plug lead.

Bank 1 circuit malfunction sounds like a fault in the whole ciruit rather than the cam sensor (there is only one sensor anyway) and the coil pack given its exposed mounting would be a good first port of call.
Jon Baker

Rob: yes its recurring. The car has had a lack of power underacceleration for a while now and I have been slowly going through what it could eb bit by bit. Apart form that it starts and runs fine, just runs at about 20bhp (slight exageration)

Jon: Its a 2000 Mpi but has lots of modificaitons in keeping with 2001 cars!! There are two coil packs attached to spark plug leads so you reckon I should replace the packs then. I have replaced leads and plugs already.

thnaks for the replies guys!

I Brown

Ian I thought your car was a VVC, so no I would not replace the coil. I didn't think the MPI had a cam position sensor as the cam period is fixed unlike the VVC. Its other use is helping the ECU in sequential rather than grouped fuelling mode.

I will have a look on my rave cd workshop manual to check.

Jon Baker

Jon - MEMS3 equipped cars all use a cam position sensor - as mentioned earlier in the thread, it is used as an alternative to the distributor - and these engines, like the VVC, use a wasted spark ignition system.

Interesting that this 2000 model year car has MEMS3... it may be an 'early adopter' - I have no idea how many cars were actually sold being EU3 compliant before the Jan 1st deadline. I'd have thought that the dealers would have been working hard trying to shift EU2 stock ahead of time!
Rob Bell

Ah, there you go.
Looking at the workshop manual the cam sensor is wired direct to the ECM as are the coil packs.
Replacing the coil pack may be the next step as the sensor signal is used by the ECM to fire both "banks" of cylinders (1 and 4 first pair - bank A?, 2 and 3 and pair - bank B?).
However the manual says that if the signal from the cam sensor is missing the engine when start and run but the fuelling may be out of phase resulting in a reduction in performance and driveablity and an increase in fuel consumption and emmissions.

So there you go !



Jon Baker

This thread was discussed between 05/07/2006 and 06/07/2006

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