2020 GMC Yukon — rough idle disappears just above idle speed

If it were in my driveway, write temp, speed, and in-gear vs coast when the 2020 GMC Yukon does it — then decide on parts. That's the branch I'd chase this week. Had a similar mess a couple years ago and that's what finally sorted it. Not interested in a five-hour wait for a shrug.

Ask what changed right before it started. Capture voltage while the 2020 GMC Yukon is actually failing — after it restarts you've lost the clue. Save the big job until that test fails. Any freeze-frame data saved? I'm in no rush to be a hero on it.

Intermittent stuff lies if you only catch it once. Get a real battery/charging test on the 2020 GMC Yukon, not just resting voltage, before blaming a module. If the cheap test changes it, stop and reassess. On “rough idle disappears just above idle speed,” that was the fork that mattered for me. Post the numbers (or the code) and people can get more specific. I'll poke at it this weekend.

I wouldn't throw parts yet. Write temp, speed, and in-gear vs coast when the 2020 GMC Yukon does it — then decide on parts. If the cheap test changes it, stop and reassess. Had a similar mess a couple years ago and that's what finally sorted it. If the story changes I'll post the new data.

This is usually cheaper to test than to guess. Swap the cheap/easy piece first on the 2020 GMC Yukon and see if the fault moves. You'll know quickly if you're on the wrong tree. Post the numbers (or the code) and people can get more specific. Make the next action something you can finish this week. I'm keeping receipts and dates in one folder.