Hey, I have an '03 Civic. The other day my A/C went out unexpectedly. Took it to a specialty A/C shop and they said the switch inside the cabin was bad.
Needed a new one. So we bought that. It's the control that you has the three buttons - cabin air circulation, A/C power, and defroster. A/C still didn't work.
They said there was also an issue at the PCM. Said there was now power from the inside control to the PCM, and from the compressor to the PCM. Jumper wires make the A/C work
without it, the system is dead. Said they do not service PCM's and looks like a dealership is our only option.
Here's where the plot thickens. Former owner of the car installed an aftermarket Alpine Amplifier for the radio. Worked great for a long time. A couple months
ago, the stereo system quit working. Fuse on the amp itself is still good but nothing related to radio, CD etc works. and it quit all at once.
I just assumed that the amp died. Now I'm thinking that maybe the PCM is going out in phases? is that possible?
How do I find out without spending an arm and a leg?

 

Take it to a specialty A/C shop to properly diagnose. They will check for leaks and recharge if necessary with refrigerant. Don't spend any more $ until you take it to someone who is an expert in A/C. JMHO

 

i have yet to see a bad ECU/PCM in a Honda.

so odds are pretty good that it isn't the PCM; it also wasn't the switch.