1996 Acura Integra

Air Conditioning problem
1996 Acura Integra 4 cyl Front Wheel Drive Manual 150000 miles

AC stops blowing cold when driving over 45-50mph. When Im ideling its blows cold gets down to 47 degrees. Even if im doing 60mph and throw in Nutral its starts to blow cold as soon as I put in 5th gear and engage the clutch it stops blowing cold in a minute or so. I know that my compressor clutch is good. How? I ran an + power line straight from battery. And went for a ride and my ac worked at all times no matter how fast or slow I was going.
I have checked for any leaks.
I had a shop do vacuume and re-charge my ac. They also checked the low and high pressure and replaced pressure valve. No leaks were found. I checked for any bad fuses or relays none were found.
May 11, 2010.

Hi tegyy96,

Thank you for the donation.

The AC clutch relay is activated by a ground circuit in the Engine Control Module and you might have a fault with the ECM for this circuit causing the compressor to cut off at high speeds.

The ground circuit is at ECM connector A terminal # 17. ECMs are known to fial for this circuit intermittently.

May 12, 2010.
I have all aready replaced my ECU once about 2 days ago and was getting the same problem. Now what I have figured out after long day of work is that when I disconect my speed sensor my AC seems to work fine at any speed. But as soon as I connect it it does same problem. Now I dont know if it will fix anything even if I buy a new Speed Sensor cause logically I cannnot imagine how that is tied with my AC problem?

May 12, 2010.
Sorry for the delay in replying. Had some trouble with connections and could not log in or had very slow connections for past few days.

You are correct. I could not link the VSS to the AC operations and there are no direct relationship between them. The only thing in common would be the ground circuit connection.

Try checking/testing the PCM and VSS ground circuit, located on thermostat housing.

May 16, 2010.
Ok I will try that out thanks. This is very helpfull I can at least do something about my problem, to were I didnt even know were to start. I'll keep you posted thanks.

May 17, 2010.
I have the same problem. What are the PCM and VSS ground circuits and how do I check them?

May 25, 2012.
Rick, here you go.

Jul 28, 2012.