3500 4x2 Pickup V8-360 5.9L Magnum (1994)
Overdrive Switch: Description and Operation
PURPOSE
Signals the Powertrain Control Module (PCM) of overdrive selection.
OPERATION
On vehicles equipped with overdrive, the PCM controls 3-4 overdrive up-shift and down-shift through the overdrive solenoid.
The overdrive/override switch is normally closed. When the switch is depressed the transmission will not enter overdrive, however if already in
overdrive transmission will downshift to third gear.
The overdrive switch circuit also contains a thermo-switch and coolant temperature switch. If either switch opens transmission will not shift into
overdrive.
