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 InformationRoadside Assistance Program
For U.S.-purchased vehicles, call 1-800-243-8872. (Text Telephone (TTY): 1-888-889-2438.)
For Canadian-purchased vehicles, call 1-800-268-6800.
Service is available 24 hours a day, 365 days a year.
Calling for Assistance
When calling Roadside Assistance, have the following information ready:
...
Buying New Tires
GM has developed and matched specific tires for the vehicle. The original equipment
tires installed were designed to meet General Motors Tire Performance Criteria Specification
(TPC Spec) system rating. When replacement tires are needed, GM strongly recommends
buying tires with the same TPC Sp ...
Vehicle Messages
DIC messages display when the status of the vehicle has changed and action may
be needed to correct the condition. Multiple messages appear one after another.
All messages should be taken seriously.
Vehicle messages appear as code numbers. The owner manual indicator and service
vehicle soon li ...