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

GF30.30-P-3001LE Variable Speed Limiter, Function
- with CODE (233) Distronic Plus
- except CODE (494) USA version
- as of model year 2009

Component Identification:

Function requirements of Variable Speed Limiter in general
^ Circuit 61 ON (engine running)
^ CC [TPM] (cruise control) coded in central gateway control unit (N93)
^ Electronic Stability Program (ESP) active (no fault message)
^ No kickdown
^ Vehicle speed ≥30 km/h
^ CC push button (S40/4) in variable speed limiter position (LIM indicator lamp (LIMITER is lit up)

Variable Speed Limiter, general
The Variable Speed Limiter (also known as the LIMITER or SPEEDTRONIC) is an additional function of the DISTRONIC PLUS which is integrated into the radar sensors control unit (SGR (N62/1).
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 CC push button switch are detected by the steering column tube module (N80) and transmitted to the radar sensors control unit via the chassis CAN (CAN E).

The radar sensors control unit sends the selected maximum speed via the chassis CAN and central CAN (CAN F) to the instrument cluster.

The requests to accelerate or decelerate are transmitted from the radar sensors control unit via the chassis CAN to the CDI control unit (N3/9) (for diesel engines) or ME-SFI [ME] control unit (N3/10) (for gasoline engines) and to the ESP control unit (N47-5) or regenerative braking system control unit (N30/6) (for hybrid).

A switching request at the automatic transmission is transmitted from the radar sensors control unit via the chassis CAN and drive train CAN (CAN C) to the ETC control unit (N15/3) (for transmission 722.6) or to the electric controller unit (VGS) (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 or moving the CC [TPM] switch up or down activates the Variable Speed Limiter. In this way the current vehicle speed is set as the maximum speed and moving the CC [TPM] push button switch increases or decreases it.
The CC [TPM] switch 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 electronic speedometer (A1p8) are illuminated from the beginning of the scale up to the set maximum speed. The set maximum speed is marked with an orange-colored triangle.

If a switchover to the Variable Speed Limiter takes place at the CC [TPM] push button switch, DISTRONIC PLUS is simultaneously deactivated.

Function sequence for deactivation
The Variable Speed Limiter is deactivated by:
- Moving the CC [TPM] push button to the "OFF" position
- Switching over to DISTRONIC PLUS (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)