Cruise control can't decide on a gear 4-6, something wrong?

[Tuesdak]

Rather unpleasant to use the cruise control towing on unchanging flat ground as my 2018 HO with the Aisin can't make up it's mind what gear to run. Shutting off the cruise it can settle into 5th or 6th and stay there. Tow Haul on/off no difference. I did lock out 6th at times.

Am I missing something like an engine power problem? No codes and prior to the 67A recall.

 

[STeichert]

Both of my Aisin trucks do the same thing. One is a 2017 and the other a 2018. I am also interested in a fix.

 

[AH64ID]

My 18 and dad’s 17 did the same thing. A software flash made it better, but not gone.

It really only occurred 65-72 at elevation when towing. Mine would even drop to 4th on the “hunt”.

 

[Cummins12V98]

My OE or replacement AISIN has been flawless, I must be a lucky guy!!!

 

[Learjet]

same here since new at higher altitudes, no problem at sea level. I lock out 6th and all it well.

 

[AH64ID]

My OE or replacement AISIN has been flawless, I must be a lucky guy!!!

This issue has nothing to do with hardware, it’s a software glitch.

 

[Cummins12V98]

This issue has nothing to do with hardware, it’s a software glitch.

still I must be lucky.

 

[slowmover]

The 10-Auto in big trucks had “similar” problems of TQ Demand against rear gearing. Too many times it couldn’t decide between two less than ideal gear choices. You’d have to change speed or use different ascent tactics.

12-Auto fixed that.

Pour some ice cubes over the computer, right?

.

 

[Tuesdak]

still I must be lucky.

I recall reading it's later years with the computer/software problem. Good to know the condition is "normal" and not just mine.

The dealer work order, along with the 67A recall, has a line item:
59679 - shift quality improved with PCM update.

I have had several updates for the transmission and some helped ... but never a total fix for it's inability to find first at times.