Transmission Range Operation

DESCRIPTION
The 4R44E transmission range selector lever has six positions: P, R, N, D, 2, 1. The driver selects the required gear position by moving the selector lever to the various positions. Interlocking cables and linkages connect the selector lever to the transmission. This allows the selector lever to move internal linkages and the manual control valve, which signals the driver demand.

OPERATION
Park
No powerflow is transferred through the transmission in PARK. The manual lever shaft, which is connected to a park rod, presses the parking pawl into the park gear on the output shaft. This locks the output shaft and prevents the vehicle from rolling. However, for safety reasons, the parking brake should be applied whenever the vehicle is parked.

While the engine can be started in either P or N position, the ignition key can only be removed in PARK.

Reverse
Reverse gear allows the vehicle to be operated in a rearward direction, at a reduced gear ratio. When overdrive has been cancelled, engine braking is provided in the R position with the coast clutch applied.

Neutral
As in PARK, there is no power transferred through the transmission. However, the final drive is not locked by the parking pawl, so the wheels are free to rotate. The vehicle may be started in the N position, but the ignition key cannot be removed.

Overdrive
In the position, the transmission will upshift or downshift 1-2-3-4 automatically.

When overdrive has been canceled by turning the transmission control switch on, the transmission will not upshift to 4th gear. Engine braking is provided in 1st, 2nd, 3rd and reverse gears with the coast clutch applied.

2nd Position
Selection of the 2 position provides a 2nd gear hold position from a manual upshift or downshift. When the 2 position is selected from a stop, the transmission will start in second gear. This allows for maximum traction on slippery surfaces. Engine braking is provided in the 2 position when the transmission control switch (TCS) is on or off.

1st Position
The 1 position provides a 1st gear hold after an automatic or manual downshift. The transmission is prevented from downshifting above a specific speed (approximately 48 km/h [30 mph]) to protect the powertrain from overspending. Engine braking is provided in the 1 position when the transmission control switch (TCS) is on or off.