Erasing Speed Memory
The cruise control set speed is erased from memory by pressing 
or if the ignition is turned off.
See also:
Remote Keyless Entry (RKE) System Operation
The Remote Keyless Entry (RKE) transmitter functions work up to 60m (195 ft) away from the vehicle.
There are other conditions which can affect the performance of the transmitter. See Remote Keyless ...
Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and
GPS signal reception. Cellular reception is required for OnStar to send remote signals
to the vehicle. ...
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position.
• The ignition should turn to LOCK/OFF only when the shift lever is in P (Park).
†...