Hello! I have an 08’ Yukon Denal XL and I have been experiencing an issue ONLY while the car is in drive and ONLY from a cold start and while outside temperatures are very cold as well, like freezing temps. When I start my car and drive it immediately, the first couple times I come to a complete stop and it has a vibration that reminds me of the feeling you get in a car that is a stickshift and you don’t push the clutch in, the car does not stop as it normally does, it will come to a stop but rolls a little past where it should and as the car stops, the idle gets super rough and usually the car will completely stall out. It re-starts right after. The car will do this 3-4 times and then won’t do it again until the next time I drive it from a cold start again and in cold temps outside. We were told this was a bad solenoid that was inside the transmission. We got 2 other opinions and were told this was a bad throttle body-also had a code suggesting this I believe. After having the part replaced, the car seemed fixed for approximately 4-5 weeks. Now the car is doing the exact thing again. I have also noticed lately, that sometimes when I go to accelerate after already driving on the road, coasting and then press on the gas petal again…the car doesn’t immediately accelerate, it bogs down, almost like a choking sensation and then it will accelerate. I’m not sure if this has anything to do with my big problem, but it never used to do this. I just started noticing this right after having a new throttle body put on. ??? Please help!!!
Please tell us the codes that are present.
No codes present now. The only code was for the throttle positioning sensor. It went away after the repair.
Try doing a throttle body relearn procedure to see if that helps.
The engine management may not be correctly adjusting the idle speed for engine load. Try a few experiments
When the engine seems bogged down, stopped, foot on the brake, and in D, does it unbog when putting the transmission in N?
Same thing, but instead of N, try putting it in other gears (R, 1, 2, 3 etc).
With the engine bogged down in D as before, what happens when you turn on the headlights to bright?
As above, what happens when you turn on the AC to max cold?
As above, what happens when you turn on the rear window electrical defroster?
As above, what happens when you turn the steering wheel slowly left and right?
I will have to try these and update!
Kept up on trans fluid changes? in 2wd or auto?
I don’t believe we have ever changed the fluids since we have owned the car. Its AWD.