Downhill Speed Regulation, function - GF28.19-P-3600GR

MODEL 164.1 with ENGINE 113, 156, 272, 629, 642 with CODE (219) Distronic (DTR) up to Model Year 08/Modification Year 07 vehicles with all-wheel drive (4x4)

MODEL 164.8 with ENGINE 273, 629, 642 with CODE (219) Distronic (DTR) up to Model Year 08/Modification Year 07 vehicles with all-wheel drive (4x4)

MODEL 251 with ENGINE 113, 156, 272, 642 with CODE (219) Distronic (DTR) up to Model Year 08/Modification Year 07 vehicles with all-wheel drive (4x4)

Display in the multifunction display (A1p13) of the instrument cluster (A1)

Fig 1: Identifying Instrument Cluster Multifunction Display

Courtesy of MERCEDES-BENZ USA

Downhill Speed Regulation is a system for downhill speed regulation. Using the Downhill Speed Regulation switch (N72/1s24) in the upper control panel control unit (N72/1) or with the offroad package code 430 using the Downhill Speed Regulation switch (N72s30) in the lower control panel control unit (N72) the driver can switch the Downhill Speed Regulation on or off.

The ESP control unit (N47-5) receives the signal "switch ON". A red LED integrated in the Downhill Speed Regulation switch displays whether Downhill Speed Regulation is active. A variable speed limiter or cruise control adjusted previously is switched off when Downhill Speed Regulation is active.

The minimum setting speed of Downhill Speed Regulation is 4 km/h.

In the multifunction display (A1p13) in the instrument cluster (A1) as of "ignition ON" via the cruise control switch (S40/4 or S40 with ) the setting speed of Downhill Speed Regulation can be preadjusted in 2-km/h-steps from 4 to 18 km/h. While driving downhill the setting speed can also be varied via the cruise control switch.

If the vehicle is accelerated, the Downhill Speed Regulation switches "Passive" to a speed of 35 km/h and after finishing the acceleration regulates the previously adjusted setting speed again.

If the vehicle speed exceeds 35 km/h, the Downhill Speed Regulation and the LED in the Downhill Speed Regulation switch, switch-off. In addition a warning tone appears and the message "DSR Off" appears via the multifunction display of the instrument cluster.

Function requirements

The following conditions must be met to activate Downhill Speed Regulation:

Vehicle speed <30 km/h
Downhill Speed Regulation switched on via the Downhill Speed Regulation switch
Setting speed of Downhill Speed Regulation preset in the instrument cluster

Function abort

The Downhill Speed Regulation is terminated under the following conditions:

Downhill Speed Regulation switched off via the Downhill Speed Regulation switch
Vehicle speed >35 km/h

CC [TPM] switch, component description	S40	At	GF30.20-P-2100GR
CC [TPM] switch, component description	S40/4	except	GF30.20-P-2100GT