Cruise Control Not Holding

[daveor]

I have a 1500 silverado LTZ with a 5.3 motor with auto trans. Is the cruise control supposed to help slow you down when going down hill? If I top the hill at 65, I am going at least 75 by the time I get to the bottom. My 2004 Silverado with the same engine might gain 2-3 mph on the same hill. Did they change the transmission so it was freewheeling or is something wrong with this one. I asked my service rep at the dealership. She told me to just step on the brake to slow down,,, DUH,, I already knew that. Thinking that the engine rpm's should drop to help keep the speed down. The rpm's stay right where they are at flat ground speeds. I asked one of the mechanics in the shop about it and this was the first he had heard of it. DAve

[Lincoln30]

No, cruise control never slows you down on GM vehicles, they simply let off the gas and coast when necessary. I find the GMT900 coasts more freely then my GMT800 does so it slows down less when using the cruise downhill because it coasts better (does that make any sense???)

[alaska511]

No, cruise control never slows you down on GM vehicles, they simply let off the gas and coast when necessary. I find the GMT900 coasts more freely then my GMT800 does so it slows down less when using the cruise downhill because it coasts better (does that make any sense???)

 

 

Well, the 1500s that is.

The HDs w/ Allisons have grade braking in T/H mode, it will hold set speed no matter what...

[daveor]

No, cruise control never slows you down on GM vehicles, they simply let off the gas and coast when necessary. I find the GMT900 coasts more freely then my GMT800 does so it slows down less when using the cruise downhill because it coasts better (does that make any sense???)

But mine does not let off the gas, the rpms stay the same, my 2004 dropped the rpms waay down. DAve

[mljenkins]

My '06 on a good hill with 4.10 gears will get going pretty fast without the brake. I don't have that many steep hills on the highway and the one that I do it stays around 5 mph above speed limit so it doesn't bother me.

[dannynoonan]

My 08 coasts way more freely than my 99. I let off the gas about a block before a red light and only drop 5mph before i get there. I stayed on the gas in my 99 till 150 yds. It seems to help quite a bit with the gas mileage.