ltooz_a6_a8_q7

OK guys, I've been reading about the Audi AC system for a few days now and I think I have some ideas about it. I'm going to create a thread that show how I'm going to fix the common problems that many of A8 people have. This one I think would save people time and money, although I had to put time in to create all these videos. Again, I'm illiterate so I prefer comics over novels.

I tested with 3 conditions -
No Freon: VCDS will show Under Limit Exceeded - The ECON CANNOT be set to OFF , system will revert it back to ON (AC OFF).
No G65 plugged in: VCDS will show Short or Open to Ground but the ECON CAN be set to OFF (AC ON) if Freon is present in the system.
Freon charged with leaks


I believe there is NO WAY the compressor can be damaged with all the fail safe sensors they put in place - G65 8E0959126 (3R0959126 new version) and N280 inside the compressor itself.

When you charge the system without weight scale, make sure the system is emptied - charge with the first 12 oz can - but here is the trick:

When the low side get above 60 PSI, close the valve and wait a little for the high side to kick in, then open again.

If the system is working this is what it should do

If you get the High Pressure Sensor (G65) problems. This may be the cause

If you need to replace the G65 High Pressure Sensor.

If you need to replace the Orifice or Restrictor.

If you want to remove AC compressor or N280 Sensor.

If you want to test the system for leaks.

Cheers,

Louis

the_duke

I hope I never need any of this but thank you for taking the time to make the videos and post them here.

Junius

Did you ever fix your a/c problem? Hopefully so

ltooz_a6_a8_q7

I'll be testing it tonight or tomorrow. The worst case is getting a new one at the dealer 3R0959126 for $105.

Cheers,

Louis Le

newmoon

Wow this problem still occurs on newer Audis including my 2012 A6. Except the pressure switch is G395, TSB# 2020124/12, and the revised part is 4H0-959-126-A.

aTOMic

Wow, Louis, you have my condolences on the loss of your front end!

Looks like a huge job!

Thanks for the write-up, you have really become an ASSet to AW. Really.

hunterp27

Louis,

I hope your A/C is working when you get it charged. When you say that your wife is patching the leaks, what are you referring to? Leaks where? and what is she doing to patch them?
I looks like your compressor is much much more accessible than on my S8. Additionally, the S8 doesn't have the N280 sensor. There is simply one electrical connector and the in and out for the refrigerant.

carl viking

Very nice of you to create this an put it in one place. Thank you!

JohnnyJ A6Q

Very nice Louis !!!

ltooz_a6_a8_q7

When she took to the lab, the air escape from the valve through the electrical connectors pin 1 to pin 3. She put epoxy to seal the leaks, I think she shouldn't plug the surrounding of the valve pin. She insists that the air go through the center metal pin and not the surrounding area.
I bought one from NAPA and it didn't even fit.
Looks like the next one is the original from dealer $105. I can order from ECS or AudiUSAparts to save 20%.
I'll build a 50hz 50% duty cycle circuit to fake the system that the G65 is working on Monday.
If it doesn't work, then the next step is to remove the AC compressor a open it up to see before I order a new compressor. I still don't believe the compressor can be bad with all these failsafe sensors protection.







One question: When I try to release the serpentine belt tensioner, the 19mm bolt only moved a little and stuck, it's enough to loosen the belt, but there wasn't enough movements to find the hole to stick the pin through the bolt to lock. Anything else I need to do?

Where I work and be in the industry that I am, sometimes I must be an ASSet to the company. Life is too short to be vague, lazy and produce bad results. Do you know that Steve Jobs was famous as an ASSet to Apple? "I'm illiterate, I prefer comics over novels" is actually quote from Managers for Engineers who write procedures without pictures or videos. When a production line oversea (since we outsource) stops because operators don't understand the written procedures... well, you may not know that. This day and age, most people have a camera with them at all time, a simple click, "A picture is worth a thousand words". Marketing people who are vague, nothing can be designed or built correctly. Results that count.

Cheers,

Louis