Hi,
That's a tough one. The idea that the compressor is always engaged regardless if it is on or not can be causing the issue.
Are you certain that the compressor clutch is engaged and it's not just the pulley turning? If you are, disconnect the compressor. See pic 1 below. See if that causes the clutch to disengage and the idle to change to normal.
When the A/C is engaged, the engine idle speed should be slightly increased to compensate for the added load. However, if it is always engaged, that is going to throw things off.
Also, a rough idle can be caused by an engine vacuum leak. Check for that as well. Here is a link that shows how it's done:
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
If none of this helps, then I recommend having the can-bus scanned for diagnostic trouble codes. CAN stands for controller area network. Basically, all the computers/modules are tied together via a few wires. This will retrieve codes regardless of the module it's stored in.
Here is a video showing it being done:
https://youtu.be/InIlnsjOVFA
Let me know what you find or if you have other questions.
Take care,
Joe
See pic below.
Image (Click to make bigger)
SPONSORED LINKS
Tuesday, August 3rd, 2021 AT 8:42 PM