A/C not working and code P0641

THANSON82

MEMBER
2007 CHEVROLET SUBURBAN
6.0L
V8
4WD
AUTOMATIC
143,000 MILES

A/C stopped working we checked everything ended up replacing the entire system plus some. A/C still wouldn't turn on. It will jump and the clutch engage with the paper clip trick but that's it. Now it's throwing a low voltage code p0641 when the connector to the compressor is plugged in, unplugged its fine. We replaced the connector and bad wiring there now its won't engage with the paper clip trick and blows a the fuse and the code will throw. Help! Also check the control board for it and it reads fine.

Thursday, July 8th, 2021 AT 5:57 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,136 POSTS

Hi,

The code indicates a voltage issue to the A/C pressure sensor. It should have a 5v reference. The code indicates it is either too high or too low.

Disconnect the pressure sensor and check the voltage to it. It should be between 4.8v and 5.2v. This will help us determine if there is a short to voltage or a short to ground.

Also, I attached information below related to this code. Take a look through it and let me know if it helps.

Here is a link you may find helpful when testing:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

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