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.

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5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)