2003 GMC Sierra 1500 Pickup Owner's Manual - Page 110

Retained Accessory Power (RAP) Your vehicle may be equipped with a Retained Accessory Power (RAP) feature which will allow certain features on your vehicle to continue to work up to 10 minutes after the ignition key is turned to OFF. Your radio, power windows and overhead console will work when the ignition key is in RUN or ACCESSORY. Once the key is turned from RUN to LOCK, these features will continue to work for up to 10 minutes or until a door is opened. Notice: Don't try to shift to PARK (P) if your vehicle is moving. If you do, you could damage the transmission. Shift to PARK (P) only when your vehicle is stopped. Manual Transmission The gear selector should be in neutral and the parking brake engaged. Hold the clutch pedal to the floor and start the engine. Your vehicle won't start if the clutch pedal is not all the way down - that's a safety feature. Starting Your Engine Automatic Transmission Move your shift lever to PARK (P) or NEUTRAL (N). Your engine won't start in any other position - that's a safety feature. To restart when you're already moving, use NEUTRAL (N)only. If you have a diesel engine refer to the diesel supplement for starting procedure. 2-23