Ford 2003 Mustang Workshop Manual page 2266

SECTION 307-01: Automatic Transaxle/Transmission
DESCRIPTION AND OPERATION
Range Selection
The transmission has six range positions: P, R, N, (D), 2 and 1.
Park
In the PARK position:
there is no powerflow through the transmission.
the parking pawl locks the output shaft to the case.
the engine can be started.
the ignition key can be removed.
Reverse
In the REVERSE position:
the vehicle can be operated in a rearward direction, at a reduced gear ratio.
engine braking will occur.
Neutral
In the NEUTRAL position:
there is no powerflow through the transmission.
the output shaft is not held and is free to turn.
the engine can be started.
Overdrive
Overdrive is the normal position for most forward driving.
The OVERDRIVE position provides:
Automatic shifts.
2003 Mustang Workshop Manual