Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push 
to try the call again or try again after driving a few miles into another cellular area.
See also:
Speedometer
The speedometer shows the vehicle's speed in either kilometers per hour (km/h) or miles per hour (mph). ...
When the System Does Not Seem To Work Properly
If the LDW symbol does not appear:
○ The lane markings on the road may not be seen.
○ The camera sensor may be blocked by dirt, snow or ice.
○ The windshield may be damaged.
` ...
When the System Does Not Seem to Work Properly
The following messages may be displayed on the DIC:
SERVICE PARK ASSIST: If this message occurs, take the vehicle to your dealer to repair the system.
PARK ASST BLOCKED SEE OWNERS MANUAL: This messa ...