Poor passing performance

[Tom Monaco]

I have a 2002 Yukon Denali that will not downshift when passing. The transmission shifts perfect the rest of the time. Any ideas of what to look for as to the cause?

 

[RugbyRef]

Shift solenoid? But, your going to have to take it into a transmission expert to get to the crux of the problem. It is a 2002 after all. That's a good 19 years on that transmission. The folks over in the earlier model years sections can probably help you out even more than I can.

 

[PNWYukon]

A comprehensive scan test along with transmission pressure testing should provide the required evidence.

 

[OR VietVet]

A scan is a great way to go. May end up having to do with something like this: https://www.rockauto.com/en/moreinfo.php?pk=87480&cc=1381047&jsn=2209

 

[exp500]

One similar problem I solved easily on a different vehicle- move the thick floormat!

 

[drakon543]

fly by wire engine but you still have a separate throttle position sensor. back a couple years prior you had a kick down cable for passing downshift. now it would be controlled by the tps and what the ecm sees for that system. scan tool with live data should be able to see the throttle position value. if its not seeing above a certain % of throttle position it wont shift down. as pnw VietVet mentioned. above mentioned solenoids and pressures are also a potential. but a tps is easy to diagnose and diy with the proper tools.