Stuck in EC mode. A/C never engages.

I have a 2001 Mercedes E320. It's hot summer now, but I can't turn AC on. I'm stuck in the EC (economic) mode. No matter how many times I push the EC button, it doesn't turn off. I checked fuses, recharged
freon (actually R134a). None helped. I pulled the control console out last night, but could not see a way to fix the problem. All the wires are bundled into two clusters and pluged into two sockets. Any idea what I should do? Thanks a lot.
vic
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The over/under pressure switch located on the receiver/drier has been known to go faulty. This switch will prevent the A/C engaging if there is too much or too little pressure in the system. If it is faulty then your system will not work.
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Got the same car.... two times it went in to service because of EC... both time, they replaced the evaporator temperature sensor.
Your unit has a self diagnostic code display... if I remembered correctly... set driver temp all the way up and passenger all the way down... turn off and on the ignition and code will come up... I got this info on internet... do a search on this.
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Thank you, Stratman and Tiger. I'll check the evaporator temp sensor and the pressure switch, hopefully this weekend. I just bought a set of repair manual CDs from Ebay. It says to turn driver temp all the way up and passenger all down, press the 'EC' and 'REST' buttons down together for 5-30 seconds, I'll get the self diagnostic code.
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I did the self diagnosis reading last night. Press 'Auto' on both side, then set temp to 72F on both side, then press 'REST' for 5 seconds, next is to read values on the LCD. Press 'Auto' for next value. The only suspicious value I saw was 7 on left side and 05 on right side. I looked up on the manual. It means refrigrant pressure is 0.5. That might be too low.
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I have a '98 SLK - there is a single 50amp fuse in the Air Conditioning control unit - took me ages to find it when I had a radiator problem

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Then you got to charge it up.
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wrote:

Hi, this thread caught my eye due to my '97 C230's weak and intermitant AC.
Attempting the above, almost worked, but I needed to: [AUTO] temp at 72 (is this necessary?) hold [REST] for 5 seconds values appear on LCD as alternating 01 98f (I could change codes by pressing + and - of fan speed control)
others I got were 02 80f 03 79f 05 124 06 167 07 06<degree>9 which I assume is refrigrant pressure of 06.9 ... I assume I need to re-charge the system, but I don't know what the other numbers mean, is there a link to this information?
BTW: upon reving up the engine the 07 number changed to 16<degree>4 and stayed higher, and the AC blew colder.
reagrds, Bob
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02 -- outside temperature 03 -- heater core temperature (left) 05 -- evaporator temperature 06 -- ECT sensor (sorry, I don't know what ECT stands for) 07 -- refrigerant pressure in bar
I have a repair manual.
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"" wrote: > 02 -- outside temperature > 03 -- heater core temperature (left) > 05 -- evaporator temperature > 06 -- ECT sensor (sorry, I don't know what ECT stands > for) > 07 -- refrigerant pressure in bar > > > I have a repair manual.
Hey, thanks guys for this great topic here. I got a 96 C220 with the same EC light on for over a year and didnt know what the problem was with my AC not working. I followed the details here and found that at 07 it showed my refrigerant to be LO. So I filled in more R134a stuff and it showed pressure until I was able to physically press the EC button hold it in until it turned off and the compressor turned on and ac cold air came out.
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Where can you get the shop manual from ? I want one for a "2000 E320".
Does anyone know what the refrigerant pressure should be ? Mine was 04 the first time I checked and 06 the second time I checked after running the car for a while. My EC light is also stuck. My readings are as follows. 1 2x 3 4 5 62 7 8x 9' 10=.8 11=2.8 12=4.2 20=3.2 21D 22 232 24.3 and 13.5 (switches back and forth) 404 41 42@ 436
MBSam wrote:

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