2002 A/C compressor does not engage 1st try. - PeachParts Mercedes-Benz Forum

ps2cho · #1 02-24-2014, 10:04 PM

Problem (2002 CLK320...same system as E320): A/C will not start 1st time and is stuck on EC. If I restart the car, it turns on. At first I thought it was a leak, but after I put my gauges on it...not so!

My A/C gauges @ 1500rpm show Low: 35psi High 235psi
So its charged.

Could it be a sensor?
Here is the readout from the A/C control panel:

1. 70
2. 88
3. 45
4. 43
5. 40
6. 181
7. 16
8. 94
9. 25
10. 5.1
20. 4.0
21. 6
22. 0
23. 0
24. 14.1
40. 8
41. 5
42. 200
43. 134

Any ideas?

tjts1 · #2 02-25-2014, 12:36 AM

Your evaporator temp seems low. Check the evaporator temp with the AC off then turn it on, see if it drops and at what temp it shuts off the AC.

Zulfiqar · #3 02-25-2014, 10:10 AM

any error codes?

ps2cho · #4 02-25-2014, 10:20 AM

Didn't know there was a way to check!
I'll grab them tonight and post them up.

jcyuhn · #5 02-25-2014, 10:46 AM

Quote:

Originally Posted by ps2cho

Problem (2002 CLK320...same system as E320): A/C will not start 1st time and is stuck on EC. If I restart the car, it turns on. At first I thought it was a leak, but after I put my gauges on it...not so!

My A/C gauges @ 1500rpm show Low: 35psi High 235psi
So its charged.

Could it be a sensor?
Here is the readout from the A/C control panel:

1. 70
2. 88
3. 45
4. 43
5. 40
6. 181
7. 16
8. 94
9. 25
10. 5.1
20. 4.0
21. 6
22. 0
23. 0
24. 14.1
40. 8
41. 5
42. 200
43. 134

Any ideas?

It all looks very reasonable. You have:

1: In car temp: 70F
2: outside temp: 88F
3,4: Left/Right heater core temp: 45F/43F
5: Evaporator temp: 40F
6: Engine coolant temp: 181F
7: Refrigerant pressure: 16 bars
8: Refrigerant temp: 94F
etc.

Perhaps try pulling the values key on, engine off and cold. Maybe something different will appear?

The original Steve Brotherton article on diagnosing these systems is here: MERCEDES-BENZ: A/C Diagnostics & Evaporator Replacement

ps2cho · #6 02-27-2014, 01:37 AM

OK I got errors eb1 241 and 421.

What is the pulse module?
I am also guessing refrigerant fill means over filled?

tjts1 · #7 02-27-2014, 02:41 AM

You have codes B1241 (low refrigerant) and B1421 (n65 module) which controls the electric fans.

ps2cho · #8 02-27-2014, 10:15 AM

So since I have no issues at all with low refrigerant (in fact a little overcharged), is it a sensor that is bad?

This morning I missed that I could reset the codes. I did so and the pulse module error did not return. Just the low refrigerant.