I have a 2005 Suburban. I've been having issues for the past few months with the air conditioning.

While driving, the A/C compressor will shut off and start blowing hot air. This is sometimes accompanied by an odd shudder, as if the transmission isn't shifting properly. RPM issues sometimes accompany the shuddering. The check engine light comes on, and has indicated a 5-volt reference code, along with some other generic air conditioning codes. I can post codes if needed.

I've replaced the high-side pressure switch and the fuel tank pressure switch as indicated on the 5-volt system schematic. Freon has been checked and pressures are perfect. I'm a shop teacher and the auto shop teacher I work with thinks that the most likely cause of this issue is now the computer.

If the truck is turned off, sometimes the check engine light will be reset and the A/C will function normally until it starts acting up again.

Any ideas?

 

I think it may well be the ECM, as you believe it is.

 

Thank you.

Is there any way I can test the ECM to see if it is indeed failing?

 

I think you would need a professional tech with expensive tech to properly
Dx the ECM.

 

An expert can help you to fix the sensor properly.