RS6 C5 A/C High Pressure

[skiper]

Hi guys,

Recently while driving inside the city , bumper to bumpber, with 45 degrees C outside, my A/C compressor stopped and the ECON came ON with no control by pressing the button .

I stopped in the first petrol station and checked the A/C. They said that the pressure is to high in the system and the only thing they did was to replace the 600g of r-134a with new 550g of the same gas.

Yesterday I put the VCDS on, and the A/C pressure was on LO with the blower to the MAX, at 19bar .

Any idea from where this could be ?

Regards.

[Chung]

I am not sure about what your issues might be but I did have to replace my high pressure switch when I had similar symptoms. It should be noted that there are other things that can cause this but that would be my guess.

[Brav]

When I had my AC issues, it was from a bad fan controller, which basically wasn't turning on at certain times.. this supposedly made the compressor work harder, and the clutch then grenaded. may be time to replace the compressor - how many miles? did they notice any metal bits in the R134 when they evac'd it?

[skiper]

Thanks guys . I dropped the car yesterday to a workshop for few stuff and they're going to check the A/C as well.

Brav, the evac'd R134-a was ok , nothing strange there . Fans are ok . The mileage is quite high : 223k km :) .

What is the normal pressure for the A/C ?

Regards,

[kevin]

Low side should never go much over 30psi. High side anywhere from 150psi to close to 300psi on very hot days.

[skiper]

Thanks Kevin. I'll check with the workshop for updates .

[formula1man]

Just a FYI, I have used Enviro-safe rather than the 134 refrigerant as it helps the components last longer for the A/C as it is more effective.

[G2]

Typically the over pressure switch will and can activate with either excessive ambient temp, reduced air flow (town driving/"bumper to bumper", or restrictions in the High side AC. Some vehicles uses in-line filters that get clogged. Pressures are then increased and AC performance is reduced.

The low pressure switch is activated to prevent compressor damage from refrigerant/oil starvation. Each system varies but typically it's under 20 PSI. This would indicate a low charge state. Cool or cold weather will lower this value.

A high pressure reading -- on the Low side-- would indicate a poorly performing Compressor, if it wasn't over charged or ambient temps were beyond design criteria.

During the summer, I remove the under tray to help evacuate heat. It always helps the AC to work better. But then again, we don't see 45C (!). Overall, just sounds like it was too hot.

[skiper]

Guess what guys, the A/C Fan is dead , I noticed last week . I dunno since when the fan died but ... Could this be a reason for the A/C high pressure ?

And by the way : I didn't get any error on VCDS .

Regards.

[kevin]

Guess what guys, the A/C Fan is dead, Could this be a reason for the A/C high pressure ?

And by the way : I didn't get any error on VCDS .

Regards. yes, and a bad fan won't set a DTC

[marklar182]

Is there a way to toggle the AC Fan in VCDS?

I ran into this issue coming back from San Antonio last week, ECON came on and no AC. Was in Bumper to Bumper as well, has been fine since in normal driving....

[kevin]

Sure, open engine controller then go to 03 output tests.

[Chung]

Which one is the A/C fan? My system is giving me an error occasionally on my aux cooling fan. Just on the list of things to fix on my car.