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.

 

Hello! I have a 1997 C280 with the same problem fay3131 had below. When I try to reset my EC light as described by fay3131, my OOP does not flash on my climate screen. It reads OOP constantly, not flashing. Hence my EC light does not go off. Any ideas? Any help will be greatly appreciated.


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.

 

What all have you done? And is this a single or dual climate control?