C280 A/C sopped working - PeachParts Mercedes-Benz Forum

GregZ · #1 08-23-2007, 11:53 PM

Dear All,

I was out of town for two months. When I got back and started my car (it started up almost right away). She is a 2000 C280 with climate control. Anyway, I checked and the compressor is running. I could find the low port easily but could not locate the high port within 2 minutes so I could not measure the pressure, but the system does not seem to have lost the freon. Any ideas? Do these compressors have any internal relief valve that could be stuck? Where is the high port?

Thanks,

Greg

GregZ · #2 08-26-2007, 10:33 AM

Any ideas anyone?

saumil · #3 08-26-2007, 01:04 PM

Need pressure readings in this situation. Increased compressor clutch clearance could give an appearance that compressor is working but the clutch really is not fully engaged, but dont know why clearance would change while the car is just sitting. Possible that the expansion valve is not working properly, this is he only other moving part in the system besides the compressor and by not running for a while, due to lack of lubrication, it is stuck in a largely closed position.

TMAllison · #4 08-26-2007, 01:14 PM

http://www.continentalimports.com/ser_ic40142.html

AC actual values and error codes gathered from the CCU is helpful data too.

Your CCU procedures will be very similar to those described in the linked article.

GregZ · #5 08-28-2007, 04:00 PM

Thanks - that has helped.

I found a lot of info for E-class, but almost nothing for the C-class. I guess most of the sensors are the same (even though the procedure of getting to the sensor readings is slightly different as you have to pick between sensors with the fan control buttons, and sensor number and reading alternate on the screen), but how about entering the fault code mode? The climate control unit in my c-class does not have the buttons that the E-class unit is using for entering these modes.

Has anyone come across information specific to the C-class climate control?
Would the fact that there is a built-in pressure sensor for the high side explain why there is no physical connector on the high-side?

Thanks for any help!

GregZ · #6 08-30-2007, 11:48 AM

When I get the system into the "Collect Sensor Data mode", I get:
1- 88F
2- 84F
3- 87F
5- 89F
6- 196
7- 8'4
8- 98F
9- 33F
10- 125

Unfortunately I do not know how to get it into "Trouble Code" mode. I am also not sure what "9" is above and what unit "7" is in (when it is displayed there is a small circle on the top between 8 and 4. It changes with the engine RPM from about 7'8 to 11'0 (at 4000rpm)).

Any ideas?

GregZ · #7 09-01-2007, 11:51 AM

I am still not sure what those readings mean...

Thanks!