2010 GMC Savana 2500 Cargo Owner's Manual - Page 384

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. Park on a fairly steep hill, with the vehicle facing downhill. Keeping your foot on the regular brake, set the parking brake. • The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). • To check the parking brake's holding ability: With the engine running and the transmission in N (Neutral), slowly remove foot pressure from the regular brake pedal. Do this until the vehicle is held by the parking brake only. • The ignition key should come out only in LOCK/OFF. Contact your dealer/retailer if service is required. • To check the P (Park) mechanism's holding ability: With the engine running, shift to P (Park). Then release the parking brake followed by the regular brake. Contact your dealer/retailer if service is required. Parking Brake and Automatic Transmission P (Park) Mechanism Check { WARNING: When you are doing this check, the vehicle could begin to move. You or others could be injured and property could be damaged. Make sure there is room in front of the vehicle in case it begins to roll. Be ready to apply the regular brake at once should the vehicle begin to move. 7-10