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:
Reduced Engine Power Light
This light comes on
when a noticeable
reduction in the
vehicle’s performance
occurs.
The vehicle can be driven at a reduced speed
when the reduced engine power light is on,
but accelerati ...
With Selective Ride Control
1. Move the shift lever to the left
from D (Drive).
The vehicle will be in Sport
Mode. The gear indicator in the
DIC will still display a D for
Drive, and the SPORT MODE
ON message will be ...
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install ...