Cadillac Repair: 1991 Cadillac Seville Air Conditioning, 1991 cadillac seville, cadillac seville

Question
Hello, I have a 1991 cadillac seville and when the key is turned on there is a message in the fuel panel which reads "Low A/C refrigerant" "A/C compressor off". When I press the auto button it automatically goes into the econo mode and continues to read the same message. I tried your sugestion you had recommended to another person, (To clear the codes with the key on press off and warmer on the climate control panel for 5 seconds and then it will go into diagnostics. After it displays 70 on the fuel data panel push and hold off and low fan until it shows F00. Then the a/c should engage when the engine is started and put on auto.) But when I tried this procedure, a code came up reading ECM? and nothing else happened. At this point I am lost as to what to do next. How can I check to see what is wrong. If I need to boost the freon in the system, I have 4 cans which I purchased years ago before it became extinct. Can you direct me as to how to recharge this system? Thank you for any suggestions and help you can provide.  

Answer
Hi Steve, Getting into diagnostics is the same with the Seville but unfortuneatly clearing the codes is differant. To clear the codes when the ECM? appeares push the low fan button until BCM? appears, it should be the next display, then push hi fan. Continue to push lo fan until clear codes displays and then push hi fan. At that point the codes for the BCM will be gone and the a/c should work for awhile. I would advise you to wait before useing your freon because obviously you have a leak and where it seems to occur most is the evaporator core/looks like a small radiator. If you remove the module that mounts into the top of the blower motor housing...it has 2 wire connectors...and look at the core and if it looks oily and is covered with stuff then replace it first and then add your freon. You will need to get a shop to evacuate all the freon from the system before replaceing the core and then after the core has been replaced then the system needs to be drawn into a vacuum before the freon is added. It might be a good idea to have a shop leak check the system and see where the leaks are and maybe even do the repair. As a safety standpoint if you aren't carefull the freon could injure/freeze body parts and my explaining the procedure to you might not be good enough to keep you from being injured. GM has 3 day classes on how to deal with the freon and a/c systems with instructors watching to make sure that people are working safely. Bill