Overdrive Switch: Description and Operation

PURPOSE
Fourth gear is controlled by a manually operated switch in the instrument panel. The switch is in circuit with the overdrive solenoid (on the valve body) and the powertrain control module.

OPERATION
In the ON position, current flows through the switch to the solenoid for the 3-4 shift sequence. The transmission must be in third gear before a 3-4 upshift will occur.

The overdrive solenoid will not be energized and a 3-4 upshift will not occur when the control switch is in the OFF position.