2 Attachment(s)
Change the G65 Aircon Thrust/Pressure Sensor
I've had some good advice from members of this forum and so, after gaining some valuable knowledge, I thought I should try and put something back in.....
My car, an A4 2.0 TDI S-Line Avant, had a non-functioning aircon system when I bought it 3 weeks ago. The ECON light wouldn't go out and there was no cold air. I had the system re-gassed but this made no difference as one of the a/c fuses kept blowing. The garage told me it was the compressor but when I investigated later it was fuse 6 that was blowing; a 5-amp jobbie that protects the aircon pressure sensor, nothing to do with the compressor. So after some top advice from here I bought a new thrust/pressure sensor from my dealer (£57.14) and set about fitting it myself. This is what you have to do:
1. Remove the complete front bumper (no point in explaining how as there are ample articles on here and on the web with supporting pictures). I did this on my own and it took 30mins. Make sure you have a blanket underneath the car to lay it on. No need to disconnect the wires to the foglights.
2. Remove the N/S headlight assembly by loosening, but not removing, the two clamp bolts at either end of the unit (the outside one is located down a hole in the plastic moulding). Remove the screw/bolt from the top of the unit, take the wire cluster from the back and it will pull out.
Once out this is how it will look:
Attachment 17358
The thrust sensor is located just left of centre in the image above. On the car it sits on a spigot that leads from one of the a/c pipes that follows the N/S of the radiator. As I tried to disconnect the plug the whole outer shell of the unit broke away and what was left was full of corrosion. I took this as an encouraging sign; after the rigmarole of removing the bumper I would have been disappointed to have found everything in working order!
Here is a close up of the corroded sensor:
Attachment 17110
I put on a pair of motorbike gloves and some sunglasses and set about removing the remains of the sensor. You'll need an open-ended 17mm spanner to do this. Mine came off very easily but I'm told they can be tight all the way off the thread. Anyway, the system has a schrader type valve on the spigot and so minimal gas is vented - it certainly doesn't need to be re-gassed afterwards (assuming you have a charged system).
Once off, clean the thread and make sure the O-ring is okay before screwing the new sensor on. It doesn't need to be horribly tight; just up and then a good nip. While the bumper is off I took the opportunity to lube the threads of the headlight clamps and squirt WD40 over the corroding metal parts.
I was fortunate; when I started the car I was able to push AUTO and the ECON light went out. This was accompanied by a slight drop in RPM and cold-ish air filling the cabin - hurrah!
So, if you have no aircon and the ECON light doesn't go out when you press AUTO then this should be one of the routes you check before replacing the horribly expensive compressor and its attendant components.
Hope this is of help to someone.....
Re: Change the G65 Aircon Thrust/Pressure Sensor
Hi, great post. I am experiencing the same problem with my b7 s line. Can you advise what the part number is for the replacement sensor, would you get this direct from VW or can you pick these up from Audi?
Cheers
Re: Change the G65 Aircon Thrust/Pressure Sensor
I'm away on business so sorry, don't have the part number to hand. I think the sensor is common to VW and Audi so just tell them you need the G65. My dealer said it was a stock item as they fail all too frequently.
Someone else on here managed to change the sensor without removing the bumper first but I'd take the front off to make it easier to get to everything.
Re: Change the G65 Aircon Thrust/Pressure Sensor
Hey guys, just changed this sonsor but econ light still wont go out, do i need to get the codes cleared or something or could it be a fuse? is so any info would be appreciated, cheers
Re: Change the G65 Aircon Thrust/Pressure Sensor
thanks for the reply mate, na its not the gas, the first thing i did was have it regassed, then changed the sensor and like i said nothing, ive since read about fuses so went and checked and surprise surprise the fuse was blown, so replaced it, and the econ light goes out but theres no change to the air being delivered at all (no cooling) so im fearing the worst i.e compressor now, anyone have any ideas before i go to audi and pay through the nose?
Re: Change the G65 Aircon Thrust/Pressure Sensor
No idea mate i cant see when looking down the front of the engine bay, is there any way to check, there doesnt appear to be any sound, any ideas how i can check for sure?
Re: Change the G65 Aircon Thrust/Pressure Sensor
Look deep down it'll be driven off the crankshaft pulley,see if the clutch spins when operating the econ switch,the clutch not just the pulley.Next check if its being commanded to operate by seeing if there's voltage on the connector.
