Operation CHARM: Car repair manuals for everyone.

External Controls

External Controls
The selector lever linkage transfers the selected transmission operating mode from the selector lever to the transmission. The selected mode of operation, shown on the selector lever indicator, is transferred through the transmission column shift selector tube, then to the selector lever cable and down to the manual control lever on the transmission.

Brake Shift Interlock System
The brake shift interlock system prevents shifting from PARK unless the brake pedal is depressed. The brake shift interlock system consists of a brake shift interlock actuator mounted at the base of the steering column tube. If the ignition switch is in the RUN position, the brake shift interlock actuator is continually on unless the brake pedal is depressed.

Transmission Control (TC) Switch and Transmission Control Indicator Lamp (TCIL)
The transmission control (TC) switch and transmission control indicator lamp (TCIL) are located inside the end of the selector lever. For vehicles equipped with a 4R70E/4R75E and a TorqShift with a diesel engine, pushing the TC switch will either disengage or engage the overdrive function of the transmission. When overdrive is disengaged, the TCIL will illuminate the word OFF. Each time the ignition switch is placed in the RUN position, the transmission will automatically provide overdrive operation regardless of TC switch position the last time the vehicle was running.

Tow/Haul
Both 5.4L and 6.8L engines equipped with a TorqShift transmission use Tow/Haul instead of OD cancel. Pushing the TC switch will either engage or disengage the Tow/Haul function of the transmission. When Tow/Haul is engaged, all forward gears are available. With Tow/Haul disengaged, the word OFF illuminates on the indicator.