Cruise control hunting

[jeff1216]

O5 LLY.......Cruise works fine...Just seems to be slightly on off gas on flat ground.......Normal?

[More Power]

In the beginning, GM introduced the LB7 with about a 1-mph window for the cruise to work in. This was fine when running empty, but created what was later termed "busy shifting" when loaded, as the transmission would drop into direct while towing up any sort of mild incline, like crossing a highway overpass.

GM later widened that cruise window to about 4-mph, which helped considerably with the busy shifting many people complained about.

The 4-mph window works great whether loaded or empty - till you add a performance product. The increased power causes the engine to constantly "hunt" to maintain speed, and is most noticeable when running empty. I find it annoying, and turn off the extra power when traveling.

If you're not using a performance product, you may need to visit the dealership to see if any programming updates are available for your truck.

Alternately, you could visit the ECM/TCM Update (http://vci.ecomm.gm.com/vci/) page at GM to see if any updates apply in your situation. You'll need to input your VIN number when accessing this link (click the colored text). smile.gif

MP