At constant speed (most any speed) the truck bucks, and you can see it on the tachometer gauge?

2012 GMC ACADIA
150,000 MILES • 3.6L • V6 • 2WD • AUTOMATIC
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ROCKSTAR_X3X
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  • 2 POSTS
However, when you switch on the cruise control, it straightens out. Throttle position sensor? Is that available for this vehicle? Whole pedal assembly? TIA
Dec 18, 2023 at 10:17 PM
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STRAILER
  • ✓Experienced Mechanic
  • 55,224 POSTS
It sounds like you have an engine misfire, the tachometer will jump if you have a misfire as well. The TPS is integrated into the throttle body, but we should run the codes, so we don't guess as to what the problem is. Let's start with this guide:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please upload videos of the problem so we can see what's going on and let us know which codes are listed.


Dec 19, 2023 at 5:18 AM
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