2009 GMC Savana Van Owner's Manual - Page 107

The length of time the heater should remain plugged in depends on several factors. Ask a dealer/retailer in the area where you will be parking the vehicle for the best advice on this. { CAUTION: It is dangerous to get out of the vehicle if the shift lever is not fully in P (Park) with the parking brake firmly set. The vehicle can roll. Do not leave the vehicle when the engine is running unless you have to. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure the vehicle will not move, even when you are on fairly level ground, always set the parking brake and move the shift lever to P (Park). See Shifting Into Park on page 2-27. If you are pulling a trailer, see Towing a Trailer on page 4-28. Make sure the shift lever is fully in P (Park) before starting the engine. The vehicle has an automatic transmission shift lock control system. You must first press the brake pedal before you can shift from P (Park) with the ignition in ON/RUN. If you cannot shift out of P (Park), ease pressure on the shift lever and push the shift lever all the way into P (Park) as you maintain brake application. Then move the shift lever into another gear. See Shifting Out of Park on page 2-29. 2-23 Automatic Transmission Operation There are several different positions for your shift lever. P (Park): This position locks your rear wheels. It is the best position to use when you start the engine because the vehicle cannot move easily.