Steering wheel gear shifter component description - GF27.19-P-1201SX

TRANSMISSION 722.9 in MODEL 216.371, 221.022 /028 /054 /056 /070 /071 /080 /084 /086 /122 /128 /154 /156 /170 /171 /180/184 /186 up to Model Year 8

Fig 1: Identifying Left/Right Steering Wheel Gear Shifter

Courtesy of MERCEDES-BENZ USA

Location

The left steering wheel gear shifter is located on the left on the back of the multifunction steering wheel and the right steering wheel gear shifter is located on the right on the back of the multifunction steering wheel (MFL).

Task on vehicles with code (494) USA version

The left steering wheel gear shifter and right steering wheel gear shifter have the following tasks:

Preselection of shift range.
Shifting into a gear from which the vehicle can be favorably accelerated or decelerated.

Task on vehicles except code (494) USA version

The left steering wheel gear shifter and right steering wheel gear shifter have the following tasks:

Preselection of shift range.
Shifting into a gear from which the vehicle can be favorably accelerated or decelerated.
Direct switching of all forward gears in manual program "M"

Function

The left and right steering wheel gear shifters are read in by the steering column module (N80) via the steering LIN. The steering column module places the "upshift" or "downshift" signal on the chassis CAN. The fully integrated transmission control (VGS) control unit (Y3/8n4) on model 221 receives the signal via the ME-SFI [ME] control unit (N3/10) or the CDI control unit (N3/9) and triggers the gear change.

On model 216 the fully integrated transmission control (VGS) control unit receives the signal via the ME-SFI control unit and triggers the gear change.

Shifts, which would result in impermissibly high or low engine speeds, are not performed.