Camshaft G40 Sensor

A5/S5/RS5
#1

Hi
Iv’e got a annoying problem with my RS5.
More often so is the camshaft sensor G40 showing up. I have changed the sensor to a new one and I have also swapped the sensors around with no good luck, so I dont think its an sensor problem. The engine has only been driven 4000Km from new. So there is proberly not any problem whith missalignment on the cam.

But I think its an electrical problem. Maybe the voltage on terminal 30 is the problem. How can I check the voltage from terminal 30?
Please guide me in the right way to solve this.

1 Fault Found:

4113 - Camshaft Position Sensor (G40)
P0341 00 [232] - Implausible Signal
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 4
Mileage: 139646 km
Date: 2020.08.08
Time: 16:27:33

                Engine speed: 1754.00 /min
                Normed load value: 58.0 %
                Vehicle speed: 0 km/h
                Coolant temperature: 24 °C
                Intake air temperature: 27 °C
                Ambient air pressure: 1010 mbar
                Voltage terminal 30: 10.554 V
                Unlearning counter according OBD: 40
#2

Intermittent codes can be the worst. The upside here is checking the voltage is a good idea.

Looking at your fault code 10.5v seems incredibly low. But generally speaking I would expect to see a higher voltage.

to me this looks like start up when the rpms are falling from initial start

Obviously for me. I would start by looking at all of the values with the car warm. The cam values and then if you can you might be able to log terminal 30? That is a long shot but it’s worth looking into the vag channels just to see.

After you see what the values are then log when the car starts to see if there are any big gaps. The only odd thing I see is there are no pointing to what bank it is.

1 Like
#3

Sometimes, what can happen is another aspect of the engine is out of spec, specifically fuel or ignition timing related, even oil level. If that happens and the engine asks the cams to do something it can’t you get an implausible signal.

I’d start with the cheapest fix first, checking voltage. I think there is a way to check using the VCDS but I’ve not gone into that block to try and monitor voltage myself. Might have to hit up the VCDS forum and ask. They may have a YouTube video.

Cars don’t like to sit and sensors can oxidize without use and heat cycling. Cam sensors are particularly prone to this and it happens on other makes and models when they sit for long periods of time. Also, check for visible wiring damage. Rodents like Audi wiring harnesses for some reason. I used to daily drive mine and it wasn’t a worry but now, in the age of COVID, the car sits for a week or more. I check for signs of rodents frequently!

I would probably chalk it up to something else. You won’t always get a code for something that’s slightly out of spec but hasn’t gone “bad enough” to trigger a cel. Could be 02 sensors or even a high pressure fuel pump on that bank.

2 Likes
#4

There is a camshaft test in Vagcom I haven’t been able to do. If you pass that test it is likely the oil level. Well documented on VAGs; the pressure plays in to set the camshaft’s position. I started topping up the oil a bit more often. The frequency is low or how do you read that from the log, four faults since reset? I have not had it come back since I topped up although I have hardly moved the car for months.

#5

Yeah have to look at frequency. As we discussed in the other threads, I suspect if you start seeing increased oil consumption, you may be looking at the PCV’s going bad. I’m shy of 70K and replaced both of mine but I’ve also switched back to Motul which always seemed to have better results in that department. Now using Motul Sport which is 100% ester and I’ve not had to top off despite having bad PCV valves.

#6

Hi @Pontus was that the battery or is it an AGM or what was the issue?

#7

People are also discovering the VVT sensors can cause cam sensor codes. Makes sense. I pulled mine to look at them and at 75K miles, they looked pristine. I ruined one trying to “clean” it so don’t do that, LOL.