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:
Airbag System Check
The airbag system does not need regularly scheduled maintenance or replacement. Make sure the airbag readiness light is working. See Airbag Readiness Light on page 5‑20 for more information.
No ...
Lap-Shoulder Belt
If the vehicle is a regular cab, then all seating positions in the vehicle have a lap-shoulder belt. If the vehicle is a crew or extended cab, then all seating positions in the vehicle have a lap-shou ...
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 dri ...