O/D Off Switch Description

WARNING: This page is about a different car, the 2002 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.

A momentary type O/D OFF switch is attached to the selector lever knob.
It has no difference in switching positions. O/D OFF mode can be selected by turning the O/D OFF switch ON and OFF.
As a safeguard, the O/D OFF mode is canceled when the ignition switch is turned OFF. The O/D OFF switch turns ON/OFF by the O/D OFF switch internal circuit.
The PCM detects the internal circuit switching and selects O/D OFF mode.

See Figure.