Audi Logic

I located two switches under the front bumper
of the 96 A6
one is green and the other is red
which is which....
the only other switch is up by the windshield
and I know thats the low pressure switch..

I'm getting a code that says high pressure switch stuck or shorted to +

Audi Logic

I tested the high side since its the only available port..
I got 110 PSI with the system off at 84 degrees
and 310 with the system running same temp

310 seems to be high to me
or am I wrong

Rud67

Pressure is too high. With the system off, car not running for a couple of hours, check pressure on high side it should be 68 PSI @ 70 degree ambient temperature

A6Gary

Max high pressure should be ~290 psi (20 bar).

BIG A's A^

I have been trying to add freon to the high side and have a gauge set but can't seem to overcome the high pressure side. How can you get AC in there without blowing up one of those 134 cans.

Thanks Dean Atkinson

3fordasho

the only way I've found is to remove the r134a and draw a deep vacuum in the system using a vac pump. Then with engine OFF- charge the system thru the high side port with the can upside down so you are charging the refrigerant as a liquid. This works best if you are using the large (30lb) containers and a charging scale for charging the proper amount. Any methods with the engine/ac running will result in a exploding can of refrigerant.

Audi Logic

it was about 51 degrees this morning
and the car was cold from sitting over night
I tested it and it was at 105 PSI way hight that it should be...
what I don't understand is how the pressure is so high..
the last time it was charged was last year and it worked all year long... why is it now it seem s to have too much freon???

should I just go and have some vented off or
should I get the system evacuated and recharged?

thanks for the help guys...

3fordasho

there is air or other gasses in the system other than r134a.
high static pressures do not indicate a overcharge.
Are you sure your gauge is accurate?

audiqv8

The freon is pumped in through the high-pressure schrader. To do this you need a Recovery System setup which all AC guys have on hand.

In other words take it in to have it service, unless you want the freon to gernade on you.