See also:

OnStar Mobile App
With an iPhone® or Android™-based mobile device, an OnStar mobile app can be downloaded. The vehicle can be remote started, if equipped, or the doors can be unlocked from anywhere there ...

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). ...

Trailer Brakes
Because the vehicle has antilock brakes, do not try to tap into the vehicle’s hydraulic brake system. If you do, both brake systems will not work well, or at all. Does your trailer have its own ...