See also:

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. The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). ...

Torque Lock
If you are parking on a hill and you do not shift the transmission into P (Park) properly, the weight of the vehicle can put too much force on the parking pawl in the transmission. It might be dif ...

How the System Works
When the vehicle is shifted into R (Reverse) the front and rear sensors are automatically turned on. After the vehicle is shifted out of R (Reverse), the rear sensors are turned off and the front ...