I am in desperate need of some help.  I have recently bought a MKIV Golf 1.8T 2001 model.   My ECU light keeps coming on and when i have taken it to be checked out it says that i have a faulty camshaft sensor.  I have had this replaced and the ECU light still comes on. 

I have taken this to someone else and they are saying that there are 2 camshaft sensors and that i needed to change the camshaft sensor behind the timing belt.  This i believe is the camshaft position actuator.  The only problem is that you have to buy the complete actuator which has the sensor in this and it costs about £265 to buy plus all the work involved changing this which is a big job.  Apparently as it is attached to the main body of the car a lot of things have to come off to do this job. 

Is there a cheaper way to get this problem resolved as i do not want to be changing sensors on this car and the ECU light still comes on, especially when it's costing hundreds of pounds.   I have been advised that i can open up the camshaft position actuator which is a very simple job and if i can get hold of a second hand sensor just take this out and replace it.  VW's don't sell this sensor separately.

Not sure if i am getting the right advise or if i will just be throwing money on this can and still have this problem

Please help.

A diagnostic scan of the car would certainly help us to help you.  Perhaps if we could see what faults the car is throwing we could make some recommendations.

Thanks for the feedback.  The EOBD code that comes up is P1531 and the VAG code that comes up is 17939.  

Not sure if this confusses matters but the light switched off today.  Not sure how this is possible as i assumed you could only switch the ECU light off with the machine.

Your help is very much appreciated

I found this on the P1531 code:

"P1531 Intake Camshaft Control Circuit Open" 

I am presuming this means that the solenoid that adjusts the cam timing has an issue - the circuit is open.  I'd be checking connections to see if a wire broke or if a connection is corroded.  Could be a bad ground and it could be a failed solenoid. 

Again, unless you give us more details on the car, the engine, a scan and so on, all we can do is guess.  Everything I said here could be wrong. 

As to the ECU switching off the light, it's possible this problem was intermittent and now the circuit is making contact so the ECU reset the MIL.   I think it will be back and when it comes back, please post a complete autoscan so people can offer assistance.

Thanks again for your assistance.  The ECU light has come on again and it still gives the same reading when connected to the computer.  The EOBD code that comes up is P1531 and the VAG code that comes up is 17939.

This is the only information that the read out gives me.  Not sure what else I can do to provide more info on this for anyone to help me.  You mention something about a scan.  Is this not what the computer read out does what I have provided or I should I be doing something different????

My car details are VW Golf GTI MK IV 1.8T, petrol. Chasis Number WVWZZZ1JZP282432.  Is there more information I can add to this for more assistance.

 I have had the wiring checked out and everything seems to be fine.  No fault was found regarding this.

Thanks again for all your help.

 Have you had the cambelt changed recently??

 It was changed about 15 months agao by the previous owner.

 Anyone have any more thoughts on this problem.  This light is driving me mad and i do not want tp be spending around £400 to change this sensor if this is not the problem.

Thanks

The code above says open circuit. Have you done the obvious and checked all the wiring to the sensors etc.?

To troubleshoot this problem, a copy of the wiring diagrams for the car is required.  From the wiring diagram,  trace the connections and check to see if the actuator itself has failed (open - infinite or extremely high resistance in excess of 1kohms) or if a connection has failed.  You would do this using a multimeter and measuring continuity from point to point.