Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring System. If a diagnostics check is needed between e-mails, push 
, and an Advisor can run a check.
See also:
Low Fuel Warning Light
English Shown, Metric Similar
This light comes on for a few seconds when the ignition is turned on as a check
to indicate it is working. If it does not come on, have it fixed.
The low fuel warni ...
Recommended Fuel
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If
the octane rating is less than 87, an audible knocking noise, commonly referred
to as spark knock, might be heard when ...
Manual Operation
(Fan Control): Press these buttons to increase or decrease the fan speed.
Pressing either fan button while in automatic control places the fan under manual control. The fan setting remains displayed ...