AC only works when idling
 

I have a 2005 C320 that has the AC only work when it's idling. The high side pressure was at 170psi. I added a can of freon and it went up to 220 but when I took it for a short drive it stopped working. In hindsight that seems to be the pattern even before I added the freon, and it won't come on again until everything has cooled. Ambient temperature was about 85 degrees.

I'm going to play with it some more this weekend but it's only 65 degrees out so I don't know how that will affect it.

I'm also wondering how to get the codes out of the climate control, it doesn't have a display.

What's your low side pressure?

Low is 30 psi, hi is 225 psi, vent temperature is 45 degrees.

And it's annoying the way the compressor clutch is built I can't tell if the clutch is engaged or not, the pulley has a cover on it.

At rest both Hi and Lo are at 75 psi.

There is no compression clutch. You need to be able to see both high and low side as you rev the engine.

Does this compressor have an RPM sensor?

No. It's a variable displacement compressor thats controlled by a PWM valve which adjusts the angle of the swash plate. The valve is the most likely failure point but it's impossible to tell without getting pressure readings as the engine revs up.

As near as i can tell it switches off, like the climate control doesn't like what it sees, as in a bad sensor somewhere. I've got a W202 that has a climate control that has a display and I've read codes off of that, but this car doesn't have one.

You need a start diagnostic or icarsoft tool to read codes off the w203 climate coltrol codes and live data.

I just got a message from my car
 

I stopped by a mechanic and had him read the codes from my climate control. When the AC was turned on the compressor went to 100% then 0% and said "Acceleration Active". The car was parked. Anybody know what that means and what can I do about it?

Could that be a reference to a wide open throttle (WOT) compressor cutout?
Some cars will drop out the A/C compressor temporarily when the throttle is floored.



Jim

Yes that's exactly what it means. Maybe the TPS is acting up.

What's a TPS?

Throttle position sensor..

Sixto
98 E320s sedan and wagon
02 C320 wagon

I think I found it.

Is it mounted on the throttle body, which is mounted on the back of the engine, next to the firewall, with the connector underneath it?

The transmission was taken out, it looks like they are next to each other.