1995 Honda Accord EX
2 door, manual, F22, 100% stock

Recently I had purchased a new compressor as my AC was not working. It worked flawlessly for several months and then all of a sudden stopped. I paid to have the car professionally diagnosed. Below are the notes section from the diagnostic:

Performed diagnostic testing on AC system
Found compressor not coming on
Found condenser fan not coming on
AC system pressure is ok
Perform AC system testing on AC pressure switch - good
Thermistor - good
Found compressor relay failed
Found condenser fan relay failed
Replaced both, both work
Found compressor coil still not on
Perform more testing
Found no ground signal from ECU
Vehicle needs ECU replaced and two relays
When you jump compressor relay system works and blows cold

Will I need to buy a new ECU or is there something I can do to work around this? I'm sure the ECU probably engages the compressor at only the right times so probably not. I have done some researching on the internet and have found this could possibly be from a wire that is out of place or damaged in some way. Is there an obvious visual clue if the wireing is the problem?

What model number ECU do I need? Is there anything to watch out for when purchasing an ECU, besides making sure I get a USDM one for emissions reasons?

Thanks for reading!

 

you can pick up a service manual and do some flowchart and wiring testing or you can source another ecu from a junkyard or off ebay or ht marketplace ... it will need to be the same part number as yours

 

mine is opposite of your issue!! Mine's sending a constant ground and won't stop. it eventually fried the compressor. Scared to get a new one.

 

I would get a good pinout of the ECM, and check each and every ground TO it. Normally theres several. If any are above 5ohms, find where they go, and fix it. This is laborious work, not expensive, except for time. Even if you replace the ECM, something killed it in the first place, find that something.