We need to start with what the pressure is of the high and low side of the system anytime there is an issue with the compressor not coming on.
Basically we can go through the entire system and if the pressure is assumed to be ok then we will never fix it.
Here is a guide that will help with this:
https://www.2carpros.com/articles/re-charge-an-air-conditioner-system
Once we know what the pressure is on the static system we can jump the relay to make sure the compressor comes on and actually builds pressure and the system blows code. This will confirm the entire system works and just focus on the control side.
At that point, you want to go to the pressure switch on the accumulator and check voltage. Start with unplugging the sensor and checking the gray wire for 5 volts from the PCM. If you don't have 5 volts then the PCM is the issue.
If you do then we need to check ground from the PCM using the black wire as your ground to check the 5 volt gray wire if you did not do that previously. You should still have 5 volts. This confirms the PCM and wiring is okay.
https://www.2carpros.com/articles/how-to-check-wiring
https://www.2carpros.com/articles/how-to-use-a-voltmeter
Lastly we need to monitor the voltage on the signal wire by plugging it back in and back probing the red and black wire.
This is a 3 wire sensor so you cannot just jump it as the PCM needs to see a pressure signal in order to turn the compressor on.
Please run through this material and let us know what you find with this and we can go from there. Below are the attachments needed for this.
Thanks
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Wednesday, September 8th, 2021 AT 1:29 PM