Uranium238

Hi, I have a 1999 CLK430 that is blowing hot air. I attempted to recharge the r134. Current temperature outside is 74F, and AC gauge can pressure shows just over 50psi. I see the compressor turning, EC button off, and both sides set to LO. No cold air.

I pulled the codes below, but I suspect something is going on with the refrigerant pressure switch (node 7):

1.....95
2....72
3....127
4....121
5....85
6....163
7....3 (this is very low to me)
8....91
9....-22
10....0.9
20....0
21....6
22....0
23....0
24....14.4 (voltage with engine on)
40....8
41....5
42....200
43....14


Any ideas what is making it blow hot despite a fully charged AC?

Plutoe

based on the data your compressor is shot should be 15-17bar

Uranium238

Ah bummer. Well it survived 148k mi and deserves the 21 gun salute.

andy_breuer

There is a separate Error code, you have only listed the sensor data.

Use this process and let us know what codes are returned.

Uranium238

I did this. No codes showed up at all. There wasn't even anything to clear.

andy_breuer

That #7 pressure does look low. When I recharged the AC on my 2002 CLK430 it took 3 - 12oz cans to get it going again. Then I had to do the “reset” procedure and it worked.

https://ww2-secure.justanswer.com/uploads/eurotec/2011-03-25_020013_air_conditioning_fault_codes_w208.pdf?_g l=1*1i2fzev*_gcl_au*MTA3NTE0MzUzNi4xNzE4NTUxODE2*_ ga*OTM1ODc4NzQ5LjE3MTg1NTE4MTY.*_ga_YVR58N9NM0*MTc xODU1MTgxNi4xLjEuMTcxODU1MjIzOS40MS4wLjA.

Serndipity

The N22 HVAC controller (shown in post #4 above to pull HVAC diagnostic trouble codes) is not the same as used in the W208/A208.

I posted the instructions for retrieving and erasing the W208/A208 HVAC DTCs, directly from the N22 push button control module, in post #5 in the below link.

https://mbworld.org/forums/clk-class...-less-hot.html

andy_breuer

He’s these instructions are great! Thanks!