GF30.30-P-3001FL Variable Speed Limiter, Function

GF30.30-P-3001FL Variable Speed Limiter, Function
- with CODE (440) Cruise control
- except CODE (494) USA version


Function requirements of Variable Speed Limiter in general
^ Circuit 61 "ON" (engine running)
^ Cruise control coded in the front SAM control unit with fuse and relay module (N10/1)
^ Electronic Stability Program (ESP) active (no fault message)
^ No kickdown
^ Vehicle speed ≥30 km/h
^ Cruise control lever (S40/4) in variable speed limiter position (LIM indicator lamp (LIMITER) lights up)

Variable Speed Limiter, general
The variable speed limiter (also called the LIMITER or SPEEDTRONIC) is an additional function of the cruise control, and is integrated in the Electronic Stability Program control unit (N30/4). The Variable Speed Limiter enables the driver to set an individual maximum speed in the range of 30 km/h up to the maximum speed.

The signals from the cruise control lever are detected by the steering column tube module control unit (N80) and transmitted via the chassis CAN (CAN E) to the Electronic Stability Program control unit.

The specified maximum speed is transmitted by the Electronic Stability Program control unit via the chassis CAN to the instrument cluster.A1

The acceleration or deceleration requests (to intervene in the engine control) are sent by the Electronic Stability Program control unit via the chassis CAN to the CDI control unit (N3/9) (for diesel engines) or to the ME-SFI [ME] control unit (N3/10) (for gasoline engines).

A switching request at the automatic transmission is transmitted from the Electronic Stability Program control unit via the chassis CAN and drive train CAN (CAN C) to the electronic transmission control control unit (N15/3) (for transmission 722.6) or to the fully integrated transmission control controller unit (Y3/8) (for transmission 722.9).

Function sequence for Variable Speed Limiter
The function sequence is described in the following steps:
^ Function sequence for maximum speed
^ Function sequence for activation
^ Function sequence for deactivation

Function sequence for maximum speed
The engine performance is reduced if the vehicle approaches the set maximum speed.
If this is inadequate, the service brake is actuated proportionately and if necessary, the automatic transmission shifts to a lower gear so that the set maximum speed is not exceeded (e.g. in case of steep declivity).

Function sequence for activation
Pulling on or moving the cruise control lever up or down activates the Variable Speed Limiter. In this way the current vehicle speed is set as the maximum speed and moving the cruise control lever increases or decreases it.
The cruise control lever can be moved up or down to different degrees to increase or reduce the maximum speed in 1 km/h or 10 km/h increments (two settings).

If the Variable Speed Limiter is activated at a speed of <30 km/h, the maximum speed is automatically set to 30 km/h.

When the Variable Speed Limiter is activated, the segments in the speedometer (A1p8) are illuminated from the beginning of the scale up to the set maximum speed.

If the cruise control lever is switched to the variable speed limiter, the cruise control is deactivated.

Function sequence for deactivation
The Variable Speed Limiter is deactivated by:
- Moving the cruise control lever into position "OFF"
- Switching over to CC (LIM indicator lamp off)
- Kickdown (accelerator pedal pressed by >90 % and vehicle speed <20 km/h away from selected maximum speed)
- Circuit 15 OFF (ignition OFF)