QuestionQUESTION: When driving in hot weather and having the AC on to the coldest settings, the ECM shuts everything down and I get Service Engine Soon alarm. Engine still runs OK. When pull over and restart the engine, everything is OK again. Since Cadillac uses a orifice instead of an expansion valve, then the control of refrigerant through the evaporator is made by the low pressure switch or the low temperature switch telling the compressor clutch to turn on or off, depending on the micro-processor temperature setting. What codes will I get if one or the other switch is bad? Can I replace these switches without removing the refrigerant from the system? I beleive my system uses R-12 or did they change to R-134A that year?
Thank you for your help in this matter
Joerizz
ANSWER: System came from manufacturer with R-12.
What CODES are you getting from the computer ?.
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QUESTION: Can I remove these switches without removing the refrigerant? I will download the micro, to determine if my diagnosis is correct regarding "Service Engine Soon" when running the air conditioning.
Is this correct Cadillac uses an orifice instead of a expansion valve, and the control are the two switches???
AnswerI honestly do NOT remember if the switches have a schrader valve in the line. I know the low pressure switch on the accumulator DOES have a schrader valve.
If you get the codes from the computer, It will tell you what section of the system is causing the service light.
Cadillac uses an orifice tube, YES.
