2003 Subaru Impreza Owner's Manual - Page 243

Starting and operating labor. On steep downgrades, downshift the transmission to 4th, 3rd or 2nd gear as necessary; this helps to maintain a safe speed and to extend brake pad life. In this way, the engine provides a braking effect. Remember, if you "ride" (over use) the brakes while descending a hill, they may overheat and not work properly. The engine may, on rare occasions, knock when the vehicle rapidly accelerates or rapidly pulls away from a standstill. This phenomenon does not indicate a fault. Automatic transmission The automatic transmission is electronically controlled with 4-forward speeds and 1-reverse speed. NOTE Immediately after a disconnected battery is reconnected or ATF (automatic transmission fluid) is replaced, you may feel that the automatic transmission operation is somewhat unusual. This results from erasure or invalidation of data the on-board computer has collected and stored in memory to allow the transmission to shift at the most appropriate times for the current condition of your vehicle. Optimized shifting will be restored as the vehicle continues to be driven for a while. WARNING Do not shift from the "P" or "N" position into the "D", "3", "2", "1" or "R" position while depressing the accelerator pedal. This may cause the vehicle to jump forward or backward. 7-14