Thanks Mark and Alan,

I think a can of worms may be opened when you mention that a resistance check could kill the sensor. I have heard of this before and I prefer to measure the voltage of sensors because if that is correct, then the resistance is of no consequence. If the voltage is wrong - then I would want to check continuity etc. Also, why are all my Auto-data books showing resistance values and frustratingly little of voltages?

I understand what the voltages should be but by disconnecting the sensor does not prove the integrity of the system ie. camshaft end-float etc.

Anyway, spoke to the garage this morning and they will be checking the ideas I had in my first post. Customer does not want to spend too much money, so there may not be an out-come on this.

Regards

Pete