1. check codes
2. if not codes more than likely speed sensor and launch control (you have an old version of crome that doesn't have throttle position as an option for launch...just speed and rev).

speed sensor can go bad w/o throwing a code (ie: still puts out acceptable voltage to ecu to not trip cel, but not any speed to ecu). therefore, the ecu thinks it's not moving and results in only reving to the pre-determined launch rev.

always check codes first...that almost always steers you towards the fix.