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

GF30.30-P-3001GQ Variable Speed Limiter, Function
- with CODE (219) Distronic (DTR)
- 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)
- Vehicle speed ≥30 km/h
- CC push button (S40/4) in variable speed limiter position (LIM indicator lamp (LIMITER) is lit)

Variable Speed Limiter, general
The Variable Speed Limiter (also called the variable speed limiter or SPEEDTRONIC) is an additional function of the Distronic, which is integrated in the ESP control unit (N47-5).
The Variable Speed Limiter enables the driver to set his/her own individual maximum speed in a range of 30 to 200 km/h.

The signals from the CC [TPM] push button switch are detected by the steering column tube module (N80) and transmitted to the ESP control unit over the engine compartment CAN (CAN C).

The selected maximum speed is transmitted by the ESP control unit over the engine compartment CAN to the instrument cluster.

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

Shift requests to the automatic transmission are transmitted by the ESP control unit over the engine compartment CAN to the electric controller unit (VGS) (Y3/8).

Variable Speed Limiter, function sequence
The function sequence is described in the following steps:
^ Maximum speed function sequence
^ Activation function sequence
^ Deactivation function sequence

Maximum speed function sequence
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).

Activation function sequence
Pulling or moving the CC [TPM] switch up or down activates the Variable Speed Limiter. At this time, 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.

If the Variable Speed Limiter has been activated, then the segments in the electronic speedometer (A1p8), from the start of the scale to the maximum set speed, light up.

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

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