I know what you mean, very difficult to find the correct procedures for the single zone units. Here is what I found and saved after some extensive searching a while back:

"If you have a control unit where the EC button remains illuminated you most likely have a stored DTC code or a version coding error for refrigerant level sensor. In order for the compressor to be turned on DTC codes need to be cleared and the coding needs to be corrected."


"Your Climate control unit may have to be reset. The reset works as follows: With the key in the ignition and in posistion 2 push both the defrost button and the recirc button (at the same time) for five seconds or untill the led lights in those buttons begin to flash. Wait for 30 seconds or untill the led's stop flashing. Switch off the ignition. Check the evaporator temp sensor and pressure sensor for correct functionality."

"To reset heater flaps and actuators

Switch on ignition.

Press recirculated air and defrost buttons on control panel together for longer than 5 seconds.

The LED's in the defrost and recirculated air buttons flash alternately.

Wait until the LED's stop flashing (approx 30 sec) system set to defrost LED on.

Switch off ignition.

After 40 sec re start engine."

 

Thanks

I will try it once I get back to Boston. Im back home in Puerto Rico right now enjoying my garage queen (16V). I hope it works, Im just worried if it doesnt I would need to pull the codes to see what could be actually wrong. I do know that it was cooling quite nicely after I recharged the system. I will post my results once I get back.

 

Negative results

I tried your recommendation but it didnt work. Anyone else has an idea how to get it done?

 

I have a 1997 C280 with a single temp. adjustment. I have read fay3131 post below and have a similar problem. After recharging my AC my EC light will not go off. I tried turning off my EC light according to fay3131 but in his step 2 my climate screen OOP does not flash but stays on continuously. I completed fay3131 steps but my EC light stays on until I hold the EC button in for roughly 10 seconds. Then the compressor kicks on and it cools accordingly. Is a 1997 different than a 1998? Why is my OOP readout not flashing? Will forcing the compressor on by holding in the EC button hurt my comprressor? Any help will be greatly appreciated!

THANKS!


I am posting this again as a new thread and not a reply because several people have sent messages over the last three days who have had similar problems, and I hope this helps them. This fix will only work if your AC compressor is not shot.

VICTORY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
In another forum I found an old service bulletin that showed how to reset some of the systems, so I am posting this for all future people to see. Again this is a 1998 C280 with single climate control. The EC light stayed on all the time. I replace the evap temp sensor and reg temp sensor, thanks to sleepwalker's help. Then I recharged the system with freon and 46 PAG oil. By the way you must get the compressor to come on to charge the AC if your's won't come on, then hold down EC and Rest until the EC light goes off, the compressor will kick on. After you have recharged everything turn the ignition off. Turn the key back to the second position and turn up the temp to HI and then turn the key off again. Now hold down Rest, and keep holding it while you turn the key to position 2. OOP should flash on the Climate screen. You're done. Now turn the key off and crank. Problem solved, as far as I know anyway. I made sure I posted this because my local Mercedes shop tried to tell me that I couldn't reset it without a several thousand dollar machine, and I didn't have the knowledge to fix everything. Well, I didn't have the knowledge, but I spoke to enough people on the internet to piece everything together. I appreciate everyone's help, and hope this returns the favor. The local Mercedes people wanted $550-$750 to fix the problem. So I greatly hope this helps future Mercedes owners. I know the stress that no AC can cause. By the way the system holds 1.9 pounds of freon. You can most certainly do this yourself, don't be suckered in by the repair jerks.
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I have a 1997 C280 with a single temp. adjustment. I have read fay3131 post below and have a similar problem. After recharging my AC my EC light will not go off. I tried turning off my EC light according to fay3131 but in his step 2 my climate screen OOP does not flash but stays on continuously. I completed fay3131 steps but my EC light stays on until I hold the EC button in for roughly 10 seconds. Then the compressor kicks on and it cools accordingly. Is a 1997 different than a 1998? Why is my OOP readout not flashing? Will forcing the compressor on by holding in the EC button hurt my comprressor? Any help will be greatly appreciated!

THANKS!


I am posting this again as a new thread and not a reply because several people have sent messages over the last three days who have had similar problems, and I hope this helps them. This fix will only work if your AC compressor is not shot.

VICTORY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
In another forum I found an old service bulletin that showed how to reset some of the systems, so I am posting this for all future people to see. Again this is a 1998 C280 with single climate control. The EC light stayed on all the time. I replace the evap temp sensor and reg temp sensor, thanks to sleepwalker's help. Then I recharged the system with freon and 46 PAG oil. By the way you must get the compressor to come on to charge the AC if your's won't come on, then hold down EC and Rest until the EC light goes off, the compressor will kick on. After you have recharged everything turn the ignition off. Turn the key back to the second position and turn up the temp to HI and then turn the key off again. Now hold down Rest, and keep holding it while you turn the key to position 2. OOP should flash on the Climate screen. You're done. Now turn the key off and crank. Problem solved, as far as I know anyway. I made sure I posted this because my local Mercedes shop tried to tell me that I couldn't reset it without a several thousand dollar machine, and I didn't have the knowledge to fix everything. Well, I didn't have the knowledge, but I spoke to enough people on the internet to piece everything together. I appreciate everyone's help, and hope this returns the favor. The local Mercedes people wanted $550-$750 to fix the problem. So I greatly hope this helps future Mercedes owners. I know the stress that no AC can cause. By the way the system holds 1.9 pounds of freon. You can most certainly do this yourself, don't be suckered in by the repair jerks.
Register today for free or log in if already registered to remove this ad!

I have a 1997 C280 with a single temp. adjustment. I have read fay3131 post below and have a similar problem. After recharging my AC my EC light will not go off. I tried turning off my EC light according to fay3131 but in his step 2 my climate screen OOP does not flash but stays on continuously. I completed fay3131 steps but my EC light stays on until I hold the EC button in for roughly 10 seconds. Then the compressor kicks on and it cools accordingly. Is a 1997 different than a 1998? Why is my OOP readout not flashing? Will forcing the compressor on by holding in the EC button hurt my comprressor? Any help will be greatly appreciated!

THANKS!


I am posting this again as a new thread and not a reply because several people have sent messages over the last three days who have had similar problems, and I hope this helps them. This fix will only work if your AC compressor is not shot.

VICTORY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
In another forum I found an old service bulletin that showed how to reset some of the systems, so I am posting this for all future people to see. Again this is a 1998 C280 with single climate control. The EC light stayed on all the time. I replace the evap temp sensor and reg temp sensor, thanks to sleepwalker's help. Then I recharged the system with freon and 46 PAG oil. By the way you must get the compressor to come on to charge the AC if your's won't come on, then hold down EC and Rest until the EC light goes off, the compressor will kick on. After you have recharged everything turn the ignition off. Turn the key back to the second position and turn up the temp to HI and then turn the key off again. Now hold down Rest, and keep holding it while you turn the key to position 2. OOP should flash on the Climate screen. You're done. Now turn the key off and crank. Problem solved, as far as I know anyway. I made sure I posted this because my local Mercedes shop tried to tell me that I couldn't reset it without a several thousand dollar machine, and I didn't have the knowledge to fix everything. Well, I didn't have the knowledge, but I spoke to enough people on the internet to piece everything together. I appreciate everyone's help, and hope this returns the favor. The local Mercedes people wanted $550-$750 to fix the problem. So I greatly hope this helps future Mercedes owners. I know the stress that no AC can cause. By the way the system holds 1.9 pounds of freon. You can most certainly do this yourself, don't be suckered in by the repair jerks.
Register today for free or log in if already registered to remove this ad!

It Works!!!!!!!!
I have a 1998 C230 Kompressor in Rio de Janeiro. After AC repair, the annoying EC lights remained on. I followed your instructions:
Key on position 2, set temp to HIGH, key on OFF, press and hold REST and turn key back to position 2. Display shows OOP, turn key OFF, finally crank the engine.
PERFECT!!!!!!

 

Great...jeers.

 

2001 E320 EC light stays on

I have the same problem as listed by those above and below me however I have temp controls for Passenger and another for the Drive. Because of that I do not think the other fixes will work for my car. I noticed my passenger side air was a little cooler that the driver side air at first. Now they are both not cool at all. I have not seen the compressor come on and the EC Light stays on even when I hold it down for 10 seconds or so. When I hook up the gauge to the low pressure side the pressure is way too high. I believe to charge it with freon I must turn on the compressor by turning off the ec light. Any help is appreciated. I love this 2001 E320. I only have 49K on it and keep it in imaculate shape. I just want be cool while riding in it.....oops...no pun intended.
Kevin

 

I have the same problem as listed by those above and below me however I have temp controls for Passenger and another for the Drive. Because of that I do not think the other fixes will work for my car. I just replace the whole a/c system, evaporator,compressor,condenser and expansion valve and recharge the system with fresh Freon gas and the air control unit does not get the temperature below 72 degrees so the compressor does not kick in
before the a/c was working perfect but compressor went bad and got locked,
any help on how to reset this climate control will be really appreciated, thanks

 

My car is a 1997 Mercedes E300D with the laser cut ignition key not electronic

 

I have been looking all over with negative results on how to reset the A/C control unit to stop the sticky EC mode. I can get it to go off if I press it in for about 20 sec. I laready recharged the A/C and it blows nice and cold, all I need is to reset the unit. All the instructions I found are for dual climate control units not for the one in the R129s. Thanks in advance