Shifter, Transmission: Operation: Operation
With the selector lever in position "D", the transmission control module (TCM) automatically shifts the gears that are best-suited to the current operating situation. This means that shifting of gears is continuously adjusted to current driving and operating conditions in line with the selected shift range and the accelerator pedal position. Starting off is always performed in 1st gear.
The selector lever positions are determined by a sensor assembly internal to the shift lever assembly (SLA). The sensor assembly identifies the various positions of the SLA according to the following table.
| Shift Lever Position | Bit 0 | Bit 1 | Bit 2 | Bit 3 |
|---|---|---|---|---|
| Default | 0 | 0 | 0 | 0 |
| "D" | 1 | 0 | 1 | 0 |
| "N" | 0 | 1 | 1 | 0 |
| "R" | 1 | 1 | 1 | 0 |
| "P" | 0 | 0 | 0 | 1 |
| "+" | 1 | 0 | 0 | 1 |
| "-" | 0 | 1 | 0 | 1 |
| "ND" | 1 | 1 | 0 | 1 |
| "RN" | 0 | 0 | 1 | 1 |
| "PR" | 1 | 0 | 1 | 1 |
| Implausible | 1 | 1 | 1 | 1 |
The current selector lever position or, if the shift range has been limited, the current shift range is indicated in the instrument cluster display.
The permissible shifter positions and transmission operating ranges are:
- P = Parking lock and engine starting.
- R = Reverse.
- N = Neutral and engine starting (no power is transmitted to the axles).
- D = The shift range includes all forward gears.
The shift range can be adjusted to the current operating conditions by tipping the selector lever to the left-hand side ("-") or the right-hand side ("+") when in position "D". If the shift range is limited, the display in the instrument cluster indicates the selected shift range and not the currently engaged gear.
- 4= Shift range is limited to gears 1 to 4.
- 3= Shift range is limited to gears 1 to 3.
- 2= Shift range is limited to gears 1 to 2.
- 1= Shift range is limited to the 1st gear.
Tipping the shift lever will have the following results:
- Tipping the selector lever toward "-" one time after another: The shift range is reduced in descending sequence by one gear each time, i.e., from D - 4 - 3 - 2 - 1. If the selected limitation of the shift range would result in a downshift causing excessive engine speed, the shifting is not executed and the engaged gear as well as the shift range remain unchanged. This is to prevent the engine from overspeeding. Engine retardation is low with the selector lever in position "D". To make use of the full braking power of the engine, "manual" downshifting by tipping the lever towards the left-hand side is recommended. If this has been done, subsequent upshifting must be carried out manually as well.
- Tipping the selector lever toward "-" and holding it in this position: The currently engaged gear in range "D" is indicated in the instrument cluster display and the shift range is limited to this gear.
- Tipping the selector lever toward "+" one time after another: The shift range is increased by one gear each time and the increased shift range is displayed in the instrument cluster; possibly, the transmission upshifts to a faster gear.
- Tipping the selector lever toward "+" several times: The shift range is increased by one gear each time the lever is tipped until the shift range ends up in "D".
- Tipping the selector lever toward "+" and holding it in this position: The shift range is extended immediately to "D", shift ranges are indicated in ascending sequence; possibly, the transmission upshifts to a faster gear due to the extension of the shift range.