OnStar Vehicle Diagnostics can perform a vehicle check every month. It will check
the engine, transmission, antilock brakes, and other major vehicle systems. It also
checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring
System. If an On-Demand Diagnostics check is needed, press
, and an Advisor can run a check.
Connections
OnStar Additional InformationCruise Control
If equipped with cruise control:
Press to turn the cruise control
system on and off. A white indicator comes on in the instrument cluster.
RES/+: If there is a set speed in memory, press briefly to resume to that speed
or press and hold to accelerate. If cruise control is already active, u ...
Park Brake and P (Park) Mechanism Check
Warning
When you are doing this check, the vehicle could begin to move.
You or others could be injured and property could be damaged.
Make sure there is room in front of the vehicle in case it begins to roll. Be
ready to apply the regular brake at once should the vehicle begin to move.
Park on ...
How to Add Coolant to the Coolant Surge Tank
Caution
This vehicle has a specific coolant fill procedure. Failure to
follow this procedure could cause the engine to overheat and be severely damaged.
If no problem is found, check to see if coolant is visible in the coolant surge
tank. If coolant is visible but the coolant level is not at t ...