Stuck in EC mode. A/C never engages.

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mbheadache - 14 Jun 2005 21:27 GMT

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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Stratman - 14 Jun 2005 22:40 GMT

>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
[quoted text clipped - 5 lines]
>
> vic

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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Tiger - 15 Jun 2005 01:54 GMT

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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mbheadache - 15 Jun 2005 20:36 GMT

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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mbheadache - 16 Jun 2005 15:02 GMT

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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frank hodges - 16 Jun 2005 16:58 GMT

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

>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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Tiger - 17 Jun 2005 14:16 GMT

Then you got to charge it up.

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Bob Sheff - 19 Jun 2005 20:08 GMT

>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.

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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mbheadache - 23 Jun 2005 04:10 GMT

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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MBSam - 02 Jul 2005 03:37 GMT

"" wrote:

> 02 -- outside temperature
> 03 -- heater core temperature (left)
[quoted text clipped - 4 lines]
>
> 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 didn’t 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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ron_gouldner@hotmail.com - 15 Jul 2005 14:30 GMT

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=80
2=78
3=91
4=85
5=80
6=152
7=04
8=78
9=27
10=.8
11=2.8
12=4.2
20=3.2
21=44
22=00
23=32
24=13.3 and 13.5 (switches back and forth)
40=164
41=85
42=40
43=136

> "" wrote:
> > 02 -- outside temperature
[quoted text clipped - 20 lines]
> Topic URL: http://www.autoforumz.com/Mercedes-Benz-Stuck-EC-mode-engages-ftopict124571.html
> Visit Topic URL to contact author (reg. req'd). Report abuse: http://www.autoforumz.com/eform.php?p=619196

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