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.
Checking Coolant
The vehicle must be on a level surface when checking the coolant level.
It is normal to see coolant moving in the upper coolant hose return line when
the engine is running.
Check to see if coolant is visible in the coolant surge tank. If the coolant
inside the coolant surge tank is boiling, do ...
Information Displays
Driver Information Center (DIC)
The DIC displays information about the vehicle. It also displays warning messages
if a system problem is detected. See Vehicle Messages on page 5-26. All messages
appear in the DIC display in the instrument cluster.
DIC Operation and Displays
The DIC has differ ...
Airbag Readiness Light
This light shows if there is an electrical problem with the airbag system. The
system check includes the airbag sensor(s), passenger sensing system, the pretensioners
(if equipped), the airbag modules, the wiring, and the crash sensing and diagnostic
module. For more information on the airbag ...