Thread: Cruise control allows GTP to slow down on hills

I've searched all the cruise control issues but haven't seen this one posted yet.
When pulling a hill, the cruise allows the speed to slow down. If the hill is small enough it will stay engaged and catch back up on the way down the hill. If the hill is steeper, it will disengage the cruise when the speed gets low enough. If I push on the gas to assist when going up the hill, it will stay engaged and be fine until the next hill.
Anyone ever have a Vehicle Speed Sensor create this problem? Could it be a problem with the cruise control cable?

Our sunfire does that. Slows right down when going up hill with cruise on, but it stays on and downshifts instead of canceling. Doesn't have the greatest of transmissions though. Haven't tried it since I put trans restore in it. Seemed to help shifts quite a bit. Have you tried accelerating a bit before the hill and setting the cruise and then decel if needed and set it before next hill?

I've tried accelerating before a hill and setting the cruise at the higher speed, but it still allows it to decelerate on the hill. When driving without the cruise it has no problems on the hills and generally doesn't even downshift.

just the way the cc is. it can't sense the hill till its going up it and factors change. it anin't gonna stomp it to get up it. on decel. its acting as a brake. mine does this when i use cc. ur good IMO

Originally Posted by Jakegday

hmmm, mine maintains a constant speed no matter how steep the hill. if i set it at 60, it will stay at 60, even if it has to shift into 3rd to pull up a hill, it maintains the same speed no matter what....

You don't notice that it might drop down to 57-58 then bump back up to 60 then at the peak climbs up to 61-62?

OP, what speeds are you using CC at?

Just to clarify for everyone, and thanks for the comments already, this just started a few weeks ago. Previous to that it would pull any hill of any size and not lose even 1 mph.
I tried lubricating the cruise control cable last night but it is currently below zero so I haven't had it out to give it a try.

Ya...Mine does the same. When I start to go up a hill it downshifts and pulls harder..I can hear the SC whine a little to. Once I get over the hill it goes back to normal. I never really thought about it..I thought it was normal...

As the final follow up, the lubrication of the cruise control cable seemed to do the trick. It hasn't happened at all the last few weeks. It will pull any size hill and not lose any speed.