Camshaft Position Sensor

[Dr. Bellows]

My 99 New Jetta GLS MIL light came on and my vag tool shows a camshaft position sensor failure. The Bentley manual does not show how to remove and replace this sensor. Does anyone know how difficult to change this sensor?

[boschmann]

Do you have the ABA engine with sensor on the cylinder head behind the cam sprocket or the AEG engine with sensor in the distributor? There is also a sticker on the timing cover that states which engine code you have.

[Dr. Bellows]

Originally Posted by boschmann

Do you have the ABA engine with sensor on the cylinder head behind the cam sprocket or the AEG engine with sensor in the distributor? There is also a sticker on the timing cover that states which engine code you have.

Boschmann
Ops.... I failed to mention it's a 2.0 liter 4 cylinder AEG engine.

[boschmann]

Was it code P0341? I switched the two engine codes above...you should have the sensor behind the camshaft sprocket. I assume the car still runs, therefore the sensor may be acting up sporadically or there is a wiring problem. The first check would be to make sure the connector and wiring harness are in good shape. Then you would need to check that there is at least 4.5 Volts between the outer two pins on the sensor's wiring harness.

[Dr. Bellows]

Boschmann:
My scan tool showed a Camshaft Position sensor failure. I don't remember the code since I am at work right now (have it written down at home). I checked for voltage per Bentley manual and have 5.0 volts between pins 1 and 3 so I have a bad sensor. I cleared the fault, Mil light comes on and the scan shows a camshaft position sensor failure again. The car will not accelerate and it runs pretty rough.

[boschmann]

Before deciding it's the sensor, you should do a few resistance checks on the wiring, all are done with the key off. You can check that there is less than 1.5 Ohms between the center pin #2 of the sensor harness and pin #76 (violet/yellow wire) at the ECM. You should measure the resistance between each of pins 1, 2, & 3 on the sensor harness to be sure they are infinite, not shorted to each other. You should also check between each pin and both battery ground & battery positive to be sure there are no shorts there either. If all tests are okay then the sensor is the first item to replace.

[Dr. Bellows]

Boschmann:
Thanks for the tip, the wiring checks good. How hard is it to change the sensor? The Bentley manual is not too specific, it just shows how to test the CMP.

[boschmann]

I've never had to replace one. Going from memory on the last one I saw I believe it was just held in with a bolt & pops out from the backside of the camshaft sprocket. I hope VW wouldn't do something stupid like make you remove the cam sprocket to get it out. My repair system is also vague about removing it, so that usually means it's qiute easy.