Markopolo216

Ok guys I definitely need some HELP! Been battling this thing for quite three weekends straight and can’t figure it out!

Tried to follow the TSB to the best of my ability but no such luck. I’ve replaced the G395 pressure switch with what was supposed to be an “OE” sensor off eBay and still doesn’t change anything. One of the forums I was reading suggest buying directly from Audi.

Ive also read a couple threads where people have pins pushed back in the connector. That said I went and snagged a connector from another A6 and spliced it in the see if it changes anything. Nothing!

Compressor wont run on its own but can be tested on VAGCOM and I can see the cold air coming through when output testing. Just can’t get compressor to click on otherwise.

During output test test the pressure reads 51bar. This doesn’t change even if I unplug the pressure connector while it’s running.

I also snagged the J519 out of the salvage yard A6 and plugged it in just for kicks, didn’t change a thing. So I’m sure my J519 is good.

Anyone have pin assignment for our cars? Tried my best to tap into the wires in the driver side footwell and directly into the pressure switch as well, hoping to bypass any broken wires that may be inside the loom, and still...didn’t change anything. Still blows hot air with no compressor activation.


Im seriously at a loss right now. My next plan is to try a new OEM pressure switch from Audi and if that doesn’t work I may just have them give it a whirl.

Sverige

Did you clear the error code after replacing your G395 sensor? IIRC the system needs the code deleted before it will start working again.

Markopolo216

Yes code was cleared but comes right back....

jonzie77

Are you sure you have enough charge in the system? If not the pressure switch will continue to shut the compressor off.

hrc4u

you have any log from vagcom? ful log prefered
what year car and what engine?
/H

Sam Zubel

I would do a continuity/ resistance check on the wires. Cant say how far you went with them aka end to end only because the wire diagrams so multiple connectors in between. Check resistance and voltage from fuse to connector, power wire. Resistance from connector to ground, ground wire, and grounding point. And the same from the control head connector to sensor connector, with T17H unplugged to remove J126 from the reading. Again depending how you ran your new wires. Either there is a short in the signal wire or the hvac control head J255 is defective. It says the control head evaluates the signal and determines pressure. So maybe internally its defective, or try a oem sensor. What i don't know is what the system defaults to with the sensor unplugged. Example outside air temp sensor might default to -40 degrees if unplugged. Ill attach the diagrams for you. Hope they work

-Cheers

nknauz

Did you find out what was happening? Please update thread if you did