I just returned from a weekend trip through a part of TX known as the hill country.

When the cruise control is on 70 to 73 mph and the H3 (auto trans) begins to go over a “hill”, the transmission will drop down to 2nd gear instead of 3rd gear without going to 3rd gear, with same sudden increase in speed as if you have stomped on the gas pedal down to the floor. The cruise works fine on flat roads.

I tested going up higher grade hills with the cruise off and you only need to exert slight pressure to the gas pedal to keep the same speed on the hill, not stomp the pedal as if you needed to pass someone quickly. That’s what the cruise control does, it’s as if you have applied pressure to gas pedal in a sudden manner all the way to the floor.

There are no hills that I have come across that would require the pedal to apply full gas in order to get up and still maintain the same speed.

Just wondering if anyone else has experienced this issue and what info if any you have learned from the dealer?

Thanks in advance for your help.

H30

I just returned from a weekend trip through a part of TX known as the hill country.

When the cruise control is on 70 to 73 mph and the H3 (auto trans) begins to go over a “hill”, the transmission will drop down to 2nd gear instead of 3rd gear without going to 3rd gear, with same sudden increase in speed as if you have stomped on the gas pedal down to the floor. The cruise works fine on flat roads.

I tested going up higher grade hills with the cruise off and you only need to exert slight pressure to the gas pedal to keep the same speed on the hill, not stomp the pedal as if you needed to pass someone quickly. That’s what the cruise control does, it’s as if you have applied pressure to gas pedal in a sudden manner all the way to the floor.

There are no hills that I have come across that would require the pedal to apply full gas in order to get up and still maintain the same speed.

Just wondering if anyone else has experienced this issue and what info if any you have learned from the dealer?

Thanks in advance for your help.

H30

I doubt there is anything wrong with your truck, that just seems to be the way some cruise controls work. I had a V8 Durango that did the same thing, even though it had plenty of low-end power. Same thing with an inline 6 Grand Cherokee.

Previous to the H3 was a V6 Explorer, and it was much better, although it dropped speed instead of shifting down.

I think GM's calibrations are meant to try to maintain speed, and if shifting down is what it thinks is needed, that's what occurs. I haven't been to the Hill Country yet, but on some of the big overpasses in Houston mine does the same thing.