ON our 1998 E-Class, a failed evap temp sensor caused the EC light to come on. Our readings were the same as above. Based on the diagnosis, your evap temp sensor has gone kerplunk.

I didn't change it myself as the car was under warranty, but it took the dealer just a few minutes with the car...

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

Thanks all for your help. I got the evaporator temp sensor changed, but that isn't the only problem I guess. Prior to changing it, it read about 114 while everything else read about70. After changing it, it now reads about 70 also. I also disconnected the battery hoping that might reset everything. No luck - the "Economy" light is still on and it is still giving me the following error codes:

B1231 - ECT sensor
B1234 - Sun sensor
B1241 - Refrigerant fill

Isn't B1231 referring to the sensor I just changed? If so, does that mean that maybe the codes either need reset with an OBDII scaner or maybe they will correct themselves after so many starting cycles? I have also heard that the sun sensor code is to be ignored. BTW, the refrigerant fill, Item #7 is showing 03.

Suggestions? See my next post too. Things have changed for the better!!!

Len

Well, things have changed for the better!! I decided to post my last message anyway and update things with this one.

I obtained a copy of MB Technical Bulletin that addressed the "Economy" light being on all the time. I followed their recommended procedure and my light is now off!!

Here it is:

37/99-2 GROUP 83 - MODEL 210, CLIMATE CONTROL "EC" LAMP ON: *** UPDATE TO MB-NET MESSAGE NO. 220 DATED APRIL 16, 1999, DTB 17/99 ***: If you receive client complaints on model 210 of "the EC lamp on", please check the system according to the published diagnostic and service procedures. Check if the version coding is correct. Replace the refrigerant temperature sensor in every case. If the refrigerant quantity, temperature or pressure sensors are within the specified values, the low refrigerant level indication should be switched off via the HHT or via the on-board diagnostics (P2 value) as described below. Do not replace AAC push-button modules for this complaint.
Please note that "EC" lamp low refrigerant indication is a redundant feature. Disabling this feature does not compromise the safety of the AC system, because the AC compressor will switch off if low refrigerant (level) pressure is detected.
Switching of the "EC" lamp low refrigerant level detection via the AAC Push-button Control Module can be accomplished as follows:
Switch ignition to position 2.
Set the left temperature to "HI" and the right to "LO"
Switch the ignition off.
While holding the "REST" button, switch the ignition to pos. 2. On the left side of the display, "P1" will be blinking and on the right side, the version code is
displayed. Press the "EC" button, no change is needed for the P1 value.
Press the "EC" button again. "P2", will be blinking on the left side of the display and the value on the right side.
Record this value. Using the right side temperature (red) button add 16 to the displayed value.
Press the "EC" button to store the updated version code.
Turn the ignition off and on again. Reset the left and right side temperatures to 72?F (by pressing the red and blue buttons at the same time).
For warranty, please use Damage Code 83752 04.

57/99-2 GROUP 83 - MODEL 210, CLIMATE CONTROL "EC" LAMP ON: *** REPLACES MB-NET MESSAGE NO. 461 DATED AUGUST 25, 1999, DTB 37/99 ***: On Model 210, for conditions of the EC LED lamp on although the button has not been pressed, please replace the refrigerant temperature sensor to resolve this condition. The refrigerant temperature sensor may absorb moisture may cause incorrect values to transmit to the control module causing the air conditioning system to switch off. For warranty, please use Damage Code 83752.

There is also an earlier version of this bulletin that is exactly the same except that it leaves out the recommendation to change the refrigerant temperature sensor.

Want to thank everyone for your assistance.

Len

Len,

I have an 1999 E-55. I received info from you earlier this month. I was wordering if you could tell me where the Refrigerant Temp sensor is located. I purchased a new one and can replace it if I knew where to look. I think it is loacted on the left side under the dash but don't see it readily.

Thanks for the help.

Chris

Driver's side underdash panel has to some off. Then look up under there near the front of the center console side. With the new part in hand, you should be able to spot it if you look closely for the connector wire going to it. It was tough for me to find until I had the replacement part in my hand and I knew what I was looking for.

Len

Can the sensor be purchased at a local parts store or is it only available at an MB dealer?

Thanks,
Jason

Dealer or maybe one of the World Pac guys or Phil above.

Len

Is this a picture of the sensor at the bottom of the page?
www.cashtec.net

Not shown? Click on Buy Parts above, enter your model number and look in Climate Control. A picture of it is shown there.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles

Okay, I did the r134a dye test on my C230 and I'm seeing green stuff around the passenger's side of the condenser with the blacklight. I assume that means I have a bad condenser and I should replace it and the reciever/dryer. Should I look at the evaporator too? Isn't that the component that takes the brunt of the high pressure?

Error code 1241 refrig fill

I followed the inst in the service bulletin above-thank you!, it turned off the EC light & turned the compressor back on, but still no cold air?? any ideas??

Any help would be appreciated- thank you!

ps refigerant temp sensor reads 103- 116 is that the problem?

What do the other readings say? If it's reading in F, that is not high at all for the refrigerant temp.

Here are the other readings

1 in car -91
2 outside- 123
3 heat core -98
4 heat core -96
5 evap temp -94
6 ECT -199
7 Refrig pres -9
8 refrig temp -116

Thank You,
Doug

My guess would be you are low on refrigerant but I would confirm this with a set of gauges hooked up to the low and high side taps. The #7 pressure reading of 9 bar is too low but that pressure is not taken at the same point as the tap it located. You should have low pressure in the 25-30 PSI range and high side in the 200-250ish range. You really can't be sure of what's going on until you check the pressures. Either buy a set of gauges or bring it to a professional.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Digging up an old post to thank Len for posting the procedure. It did the trick for my car.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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