2005 GMC Envoy Owner's Manual - Page 446

Automatic Transmission Shift Lock Control System Check {CAUTION: When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured. 1. Before you start, be sure you have enough room around the vehicle. It should be parked on a level surface. 2. Firmly apply the parking brake. See Parking Brake on page 2-31. Be ready to apply the regular brake immediately if the vehicle begins to move. 3. With the engine off, turn the ignition to RUN, but do not start the engine. Without applying the regular brake, try to move the shift lever out of PARK (P) with normal effort. If the shift lever moves out of PARK (P), contact your GM Goodwrench® dealer for service. Ignition Transmission Lock Check While parked, and with the parking brake set, try to turn the ignition to LOCK in each shift lever position. • The ignition should turn to LOCK only when the shift lever is in PARK (P). • The key should come out only in LOCK. Contact your GM Goodwrench® dealer if service is required. 6-10