I have a Honda Civic 2003. A few weeks ago, the air conditioner starts blowing out warm air. The mechanic told me that PCM is not working, and I need to replace the PCM. He did show me that the compressor is working, and it blows out cold air when he jumped the relay to start the compressor.

I don't know anything about car, so want to ask your opinions.

- Is it possible that a bad PCM can cause this problem?
- If I replace the PCM, what can I do with the old PCM (since everything else is still working -- it still drives fine; only AC is not working.

Thank you,
-JB