SLE3PER

In need of some help!

The AC on my girlfriends 2005 A4 1.8T is stuck in ECO mode. The code it is throwing is:

00819 - High Pressure Sensor (G65)
30-00 - Open or Short to Plus

Based on what I read I replaced the High Pressure Sensor (just under the driver or left side headlight). This did not fix the problem. The system pressure is good and I have checked the wiring back to the connector behind the driver side headlight with a meter. From there it connects to the harness that goes into the fender, so I couldn't check that part. I also checked the wires going to the compressor, they look fine as well. What else could it be? Hoping someone else has experenced this and has an answer or at least some clues.

Thanks for any and all ideas!!

Gingerbread man

Stupid question: did you clear the code after changing the sensor?

audi01a6

what is the presures in the sys?,if u cked it,

SLE3PER

Gingerbread man: I should have put that in my original post. I have cleared the code, it comes back instantly.

audi01a6: I do not know the sys pressure, I had Midas check it after I replaced the sensor. My friend has a gauge I can borrow, so I could check it tonight. What side should I check (high or low) and what should it be at in the off state?

Thanks for the help!

lyleswk

ECO staying on is usually just low refrigerant, either due to age or a leak. I suspect the switch was a sympathetic fault.

SLE3PER

Thanks guys! I picked up my buddies gauge this morning, so I will check the pressure tonight and post the numbers. Really hoping this is the problem. Does anyone know what the refrigerant pressure should be at in the off position on high/low sides?

SLE3PER

I checked the pressure at both ports and it appears that both are at 85...I'm not sure what 85 is as my buddies gauge doesn't say. It also might be a little higher as refrigerant was blowing out the side while I was testing it. The gauge isn't very fancy, looks like a tire pressure gauge with the rod that slides out. Let me know what you guys think, I'm not opposed to going out and buying a better gauge.

Prospeeder

well a good way would be find the wire going from the HVAC module to the pressure sensor, make sure there is no high resistance or open between them. If the system is charged, sensor is new, and using a meter you verify the wire is good. The HVAC controller is bad.

chad99

I just diagnosed my wifes B6 a few weeks ago (right before it got hot here) so i might be able to help a little.

How did you measure the pressure? The gauge fitting should not be allowing gas to escape if so its not the right type of gauge. also the outside temp will affect what pressure you see.

a4b64u2

Similar situation here. I jumped the compressor and the lines were cold in front of firewall so AC works. Replaced control unit with used one but that didn't do it.

Usually, Econ means a good thing.. except I'm quite sick of looking at mine lit up and no AC