Own 2003 Cayenne S with 40000 org miles. Car is like new, but suddenly AC started blowing hot.
AC compressor changed, dryer changed, system flushed, leak tested, freon levels good, AC cooled for a few days and then blowing hot again. Spent $$$ for nothing.
No fault codes showing when connected to the Porsche labtop at the dealer. Leak tested again, it is fine. Their guess is faulty control panel. My argument is the laptop would show the fault code on control panel if any.
Not satisfied with the answer. I dont want to spend more. Expert advice needed badly. Feel like buying a damn Corolla in Florida heat.

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This post was auto-generated based upon a question asked on our tech article page here:

If the system is full and the compressor doesn't come on. The scan tool should show if the pressure sensors are reading correctly, If they are and the compressor is command on, yet does not activate, the control unit may be faulty.

- Nick