Service Only Mode
This power mode is available for service and diagnostics, and to verify the proper operation of the malfunction indicator lamp as may be required for emission inspection purposes. With the vehicle off, and the brake pedal not applied, pressing and holding the button for more than five seconds will place the vehicle in Service Only Mode. The instruments and audio systems will operate as they do in ON/RUN, but the vehicle will not be able to be driven. The engine will not start in Service Only Mode. Push the button again to turn the vehicle off.
See also:
OnStar®
For vehicles with an active OnStar subscription, OnStar uses several innovative technologies and live Advisors to provide a wide range of safety, security, navigation, diagnostics, and calling servi ...
Add-on Electrical Equipment
The OnStar system is integrated
into the electrical architecture of the
vehicle. Do not add any electrical
equipment. See Add-On Electrical
Equipment. Added
electrical equipment may interfer ...
Fuel Information Button
(Fuel Information):
Press the fuel information
button to scroll through the range, fuel used,
average fuel economy, and the engine oil
life system.
Fuel Range: Press the fuel information button ...
