Camshaft sensor fault codes Golf MK7 GTI PP

[GTIlad]

Hey guys I'm wondering if you can help me diagnose what's going on with my new (to me) GTI MK7.

I had a CEL come on earlier this morning, took it straight to a garage to have the codes read. Car runs absolutely fine no limp mode / hesitancy or lumpy idle etc.

Garage found the following fault codes on the car:

14865 (P036500) Camshaft position sensor 'B' circuit (Bank 1) (Sporadic fault)

14873 (P036600) Camshaft position sensor 'B' circ. (Bank 1) Range / Performance (Sporadic fault)

Garage cleared the codes and I drove the 2 miles back home without the light reappearing. They advised me the car is probably OK to drive unless the light reappears - which I suspect it will.

Unfortunately the local VAG specialist is booked up for 3 weeks so I can't get a gauge of what I'm dealing with until I've had a proper diagnostics performed. Obviously that's quite far away so was hoping someone with some knowledge about these cars may know the issue or be able to recommend a fix. Not too keen on driving the car until I have a bit more insight into the error codes.

[Watts]

Google it, probably a diy job.

[madstaff]

Cam sensor is just to the right of coil pack no 4 (no 1 is oil filler cap end), make sure it's plugged in, no obvious damage to the wiring, etc.

Unplug, undo the retaining bolt, pull out sensor, replace.

[GTIlad]

Cheers guys.

Have had a look at the sensor and checked its resistance and did the same for sensor A - both have exactly the same resistance value. Therefore it seems unlikely it's a sensor issue although there could be more to it than that.

A good friend of mine who's a mechanic is pretty sure I may have a timing chain or adjuster issue due to the two fault codes.. Hence why I'm very cautious to drive the car.

[madstaff]

I would think if you had cam chain/adjuster issues you would be seeing fault codes relating to the 2 cam sensors, one on the inlet cam, and one on the exhuast, as it would be out of phase (timing) on both cams.

Have you checked the inlet cam sensor as its below the inlet manifold??

The fact you have checked the resistance i would discount as you say the fault is "sporadic" it may read ok when you test it and be breaking down when it gets hot for example.

[GTIlad]

I have checked these two sensors on the diagram attached at bottom of post. Sensor A8 and A5.

I’m pretty sure sensor A5 is the inlet cam sensor (sensor A) ? and Sensor A8 is sensor ‘B’ - the exhaust cam.

There is some oily residue in the area of sensor A8 as it is immediately below the oil filler cap. Perhaps this could be causing some issues with the sensor.

I see what you’re saying regarding the sporadic terminology of the faults.

Also, I’m not sure if this is relevant but the CEL initially came on after I turned onto a very tight, very steep 1st gear turn at a junction. Although just to reiterate the car is running fine and isn’t making any strange rattling noises at idle or when being driven.

Cars can be such a pain  Only picked this up on Saturday and it’s been an absolute riot to drive so far!

[madstaff]

A5 and A8 are the camshaft adjustment valves, not the cam position sensor.

You need to look at the sensor just to the right of coilpack 4, held in with a small torx bolt. (Disregard the number on the picture next to the coil pack, thats for the manual description, thats coil pack 1)

Item 6 in diagram exhaust cam sensor.
Item 9 is inlet cam sensor.
Item 12 is crank sensor.
Item 2 is knock sensor.

[joe6]

Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.

[GTIlad]

A5 and A8 are the camshaft adjustment valves, not the cam position sensor.

You need to look at the sensor just to the right of coilpack 4, held in with a small torx bolt. (Disregard the number on the picture next to the coil pack, thats for the manual description, thats coil pack 1)

Item 6 in diagram exhaust cam sensor.
Item 9 is inlet cam sensor.
Item 12 is crank sensor.
Item 2 is knock sensor.

Thanks a lot for this, very helpful. Been looking in the wrong place the entire time!

I've had the exhaust sensor (sensor B) out for an inspection and all looks OK. Was pretty stiff to remove once the plug was disconnected so the O-ring is doing its job nicely. Can't see any sign of anything wrong visually. Not really sure how to test it with a multimeter as it's 3 pin - any ideas?

I didn't bother removing the intake sensor (sensor A) as it's a lot harder to get to. Until I can find a way of testing the sensors then getting the intake sensor doesn't make much sense.

Not sure what fault code reader you have. With vcds you can measure the cam timing phase difference - engine up to temperature and running. Would check this after testing the cam position sensors. Indicates chain stretch or faulty tensioner.

This is good to know, thank you. I've just ordered a Ross-Tech VCDS HEX-V2 which should hopefully arrive tomorrow. Have you perhaps got a link or can offer any guidance on how exactly I can check this? I've never used vcds before so going in as total noob.

I'm considering driving the car around later on this evening and seeing if it throws the code again.

[GTIlad]

Just been to dealers for a new sensor. Will install and see if CEL comes back. Either way will attempt to check the timing / cam position on vcds once my cable arrives.