See also:

When the System Does Not Seem to Work Properly
The following messages may be displayed on the DIC: SERVICE PARK ASSIST: If this message occurs, take the vehicle to your dealer to repair the system. PARK ASST BLOCKED SEE OWNERS MANUAL: This messa ...

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 on page 9‑112. Added electrical equipment ma ...

Basic Trailer Wiring
All regular, extended cab and crew cab pickups have a seven-wire trailer towing harness. For vehicles not equipped with heavy duty trailering, the harness is secured to the vehicle's frame behind the ...