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:
Scheduling Service Appointments (U.S. and Canada)
When the vehicle requires warranty service, contact your dealer and request an appointment. By scheduling a service appointment and advising the service consultant of your transportation needs, your d ...
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) system makes the low-beam headlamps come on at a
reduced brightness in daylight when the following conditions are met:
○ The ignition is on.
○ The exterior ...
If No Steam Is Coming from the Engine Compartment
If an engine overheat warning is displayed but no steam can be seen or heard, the problem may not be too serious. Sometimes the engine can get a little too hot when the vehicle:
• Climbs a long hil ...