System Operation

Automatic Transaxle-Transmission External Controls - Transmission Control Switch (TCS)


System Operation

System Diagram

6F35 Only










Range Selection

This transmission has 5 range positions: P, R, N, D and L.

Selector Lever - 6F35





Park

In the park position:

- there is no power flow through the transmission.

- the parking pawl locks the final drive.

- the engine may be started.

- the ignition key may be removed.

Reverse

In the REVERSE position:

- the vehicle may be operated in a rearward direction, at a reduced gear ratio.

- engine braking will occur.

Neutral

In the NEUTRAL position:

- there is no power flow through the transmission.

- the output shaft is not held and is free to turn.

- the engine may be started.

Drive Position With Grade Assist

DRIVE is the normal position for most forward driving.

Drive provides:

- automatic shifts -1st through 6th gears.

- apply and release of the TCC (Torque Converter Clutch).

- maximum fuel economy during normal operation.

Manual L Position

In the L position:

- the transmission provides maximum engine braking.

- the transmission downshifts to the lowest available gear for the current vehicle speed.

Manual L position allows for 1st gear when the vehicle reaches slower speeds.

Gear Availability





Brake Shift Interlock

Brake Shift Interlock Operation

When the ignition switch is in RUN/START, the solenoid inhibits the selector lever movement (from the PARK position) if the brake pedal is not pressed.

The BSIA (Brake Shift Interlock Actuator) inhibits the selector lever movement from the PARK position by mechanically blocking the detent pawl of the selector lever mechanism. When the brake pedal is applied with the ignition key in the RUN/START position and the transmission in PARK, the BSIA (Brake Shift Interlock Actuator) is energized by the BCM (Body Control Module), this allows the selector lever to be moved out of the PARK position.






Proper Operation Requirements

Three requirements for the selector lever to be moved from the PARK position are:

- Ignition switch in the RUN/START position

- TR (Transmission Range) sensor in the PARK position

- BPP (Brake Pedal Position) switch closed (brakes applied - brake lamps on)

Transmission Control Switch (TCS)

Drive with Grade Assist - TCS (Transmission Control Switch)





Drive with grade assist is activated when the TCS (Transmission Control Switch) is pressed. The TCS (Transmission Control Switch) is located on the selector lever knob. When the TCS (Transmission Control Switch) is pressed, the 6th gear or O/D (Overdrive) upshift is prevented or the transmission shifts down to 5th gear. The TCS (Transmission Control Switch) is meant to be used when driving conditions cause excessive shifting from 6th to other gears such as hilly terrain, mountainous areas or when engine braking is required.

Grade Assist

- Improves vehicle handling in hilly terrain or mountainous areas by providing engine braking and extending lower gear operation on uphill climbs.

- Additional engine braking is provided through the automatic transmission shift strategy which reacts to vehicle inputs (vehicle acceleration, accelerator pedal, brake pedal and vehicle speed).

- The transmission will select gears that will provide the engine braking desired, based on the vehicle inputs, this will increase engine rpm during engine braking.

It is recommended to return to DRIVE mode on flat terrain to provide the best fuel economy and transmission function. The transmission returns to O/D (Overdrive) when the TCS (Transmission Control Switch) is pressed again or anytime the key is turned OFF.