Cruise Shift Stabilization – How/when does it work?
A. The integration of cruise control with an automatic transmission can occasionally result in excessive downshift/upshift cycling due to abrupt engine torque changes made to maintain the cruise set speed. Beginning with 2003 models, the Allison transmission and GM’s 8.IL Gas and 6.6 L Diesel GMT 800 engines are fully integrated to keep this type of shift cycling to a minimum. To this end, in addition to optimized engine throttle response rates in cruise, the Allison transmission uses a modified shift pattern in cruise which allows slightly more cruise set speed variation but results in significantly less potential for unnecessary shift cycling.
