See also:

Tachometer
The tachometer displays the engine speed in revolutions per minute (rpm). ...

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 ...

How to Detect a Tamper Condition
If is pressed and the horn sounds, an attempted break-in has occurred while the system was armed. If the alarm has been activated, the THEFT ATTEMPTED message will appear on the DIC. See A ...