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:
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp
To replace one of these bulbs:
1. Remove the two screws and lift off the lamp assembly.
A. Cargo Lamp
B. Center High-Mounted Stoplamp (CHMSL) Bulb
2. On the reverse side of the lamp assembly, r ...
Emissions Inspection and Maintenance Programs
Some local governments may have programs to inspect the on-vehicle emission control equipment. For the inspection, the emission system test equipment is connected to the vehicle’s Data Link Connecto ...
When to Change Engine Oil
This vehicle has a computer system that indicates when to change the engine oil
and filter. This is based on a combination of factors which include engine revolutions,
engine temperature, and mile ...