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 ...
Recreational Vehicle Towing
Recreational vehicle towing refers to towing the vehicle behind another vehicle,
such as behind a motor home. The two most common types of recreational vehicle towing
are known as dinghy towing and dolly towing. Dinghy towing is towing the vehicle
with all four wheels on the ground. Dolly towi ...
Climate Control Systems
The heating, cooling, and ventilation for the vehicle can be controlled with
this system.
Fan Control
Air Conditioning
Recirculation
Temperature Control
Rear Window Defogger
Air Delivery Mode Control
(Fan Control): Turn clockwise or
counterclockwise to increase or decrease ...