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 InformationHow 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 ...
Antilock Brake System (ABS)
This vehicle has ABS, an advanced electronic braking system that helps prevent
a braking skid.
When the vehicle begins to drive away, ABS checks itself.
A momentary motor or clicking noise might be heard while this test is going on,
and it might even be noticed that the brake pedal moves a lit ...
Reduced Engine Power Light
The reduced engine power light should
come on briefly as the engine is started. If it does not come on, have the vehicle
serviced by your dealer.
This light, along with the malfunction indicator lamp, displays when a noticeable
reduction in the vehicle's performance occurs.
The vehicle c ...