CigarXO

Crawled the threads and YouTube, but not sure if the C36 W202 diagnosis check for climate control is the same? As per a video I saw, with the car ignition in RUN, I pressed the <REST> and Defrost buttons simultaneously. The unit went into diagnosis (dl A). Pressing the <Auto> button did not return a sequence of sensor readings or 3 digit codes, just "60 with degree symbol" then END then Del. Full sequence:

dl A
60
END
del

I'm getting intermittent a/c. Lots of hot air. Trying to get codes before I go the Indy, charge system or replace parts.

Thanks,

CigarXO

DRBC43AMG

Have you read this thread?
https://mbworld.org/forums/c36-amg-c...control-q.html

CigarXO

DRBC43AMG - Thanks. you always come to my rescue with good advice!

I found a useful source over on the benzworld.com thread :
http://www.benzworld.org/forums/w202...-computer.html

My issue was finding the correct diagnosis process. My C36 is pre 9/95, so it is not the same. Here's a source for alot of models.
http://www.benzworld.org/forums/atta...diag-codes.pdf

Here's my results: (the car has not been run today and is outside at 58degree)
01 - 59 In-car temp
02 - 55 Outside temp
03 - 57 Heater core sensor temp
05 - 59 Evaporator sensor temp
06 - 58 Engine coolant sensor temp
07 - 03.3 Refrigerant Pressure in Bar
08 - 15 Blower control voltage
09 - 03 Software status
15 - 72 Selected in-car temp
20 - 02 Version code
21 - 00.0 Engine speed RPM
22 - 00.0 A/C compressor speed
23 - 00.0 Vehicle speed
50 - 74.0 Not used
51 - 00 Number of Current poly belt slip
52 - 00 number of stored poly belt slip

The Diagnosis returned:

dl R current
End
dl.R stored
60. A/C Compressor Electromagnetic Clutch Short Circuit intermittent
End
del


Any suggestions on next steps appreciated?

Thanks,
CigarXO

DRBC43AMG

Code 60: looks like your electromagnetic clutch is playing up. I would get that checked as this could be the problem.

CigarXO

I conducted a diagnosis of ac system with dual gauge tool. Here's the results:

at 59 degrees ambient temp.

Low Press side: 30psi Normal Range: 25-35psi
High Press side: 75psi Normal Range: 135-155psi

So, I had a Normal low side and a LOW High side.

Any thoughts?

I've got to find some place that will evacuate the existing Freon, then I'll vacuum the system, oil, dye, refill to spec. 1.9lbs of Freon and test again.

MarcusF

If this were a CLK, I'd say the system doesn't have enough Freon. I don't know what's normal for a 1995 C36, but on my 2002 CLK #7, the Freon pressure sensor, reads as follows:
Start the car, turn the AC on and DO NOT touch the gas - #7 reads as high as 15. The pressure sensor reads 7 while driving and fluctuates between 11 and 12 while waiting at lights.

My AC blows incredibly cold.

mickey13

from experience, i'd guess that there's nothing to evacuate because the freon already all leaked out, hence why the compressor isn't kicking on. you might just get some freon with dye and put like half or 3/4 a can in there and see what happens. the compressor on most cars will not turn on if it is over-pressurized and considering this is a mercedes, i'd guess the same thing.

tip. weigh the can before you fill and weigh the can after you fill to know how much you put in. yes the can might say how many oz, but thats oz of freon inside the can so that weight printed on the label will not include the weight of the can. weighing it before and after is a smart way to know how much you've put in. postal scale would probably do it.

if your compressor is leaking, which is likely the problem, you can rebuild it yourself for like $10 or you can just buy a rebuilt one with a lifetime guarantee for like $80 or less i think.

Also if you are going to test for dye, make sure you test for dye before you put any in the system. last owner or someone else may have ran dye through the system already and it might still be there and so what you think is dye from your test might be dye from a previous test.

CigarXO

Thanks for your insights...

I had the AC evacuated at a shop today. They only found .26lb of Freon.

I went home and vacuumed the system a couple more times. Then freshly charged to the 29oz spec. The car does hold vacuum pressure of -24psi for one hour.

Ran another diagnosis and here's the results:

Low Press side: 30psi Expected: 25 - 35psi
High Press side: 200-210psi Expected: 135 - 155psi

Diagnosis chart suggests: Expansion Valve or Orfice tube obstruction

The car does chill to 35F now, and MarcusF it operates at 15 Bar at idle.

Your thoughts? Thanks.