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Environment Monitoring, Basic Function - GF54.65-P-1000A

Model all (CAR) 

with code 235 (Active Parking Assist with PARKTRONIC) 

Model all (CAR) 

with code P44 (Parking package) 

Model all (CAR) 

with code P47 (Parking package with 360-degree camera) 

Overview 

This document contains the following information:

General 

The environment monitoring system scans the area around the vehicle with the aid of distance sensors in the front and rear bumpers.

It can be switched off and on manually. Environment monitoring is switched on automatically at engine start.

G12938161Courtesy of MERCEDES-BENZ USA

Function requirements 

Environment monitoring 

Environment monitoring is based on the ultrasound measurement method. The distance sensors transmit ultrasonic waves. The ultrasonic waves reflected by an obstacle are received again by the distance sensors. In principle a distinction is made between two measurements. On the one hand the direct measurement resulting from a direct echo and on the other hand the indirect distance measurement which is achieved by means of a cross echo (see illustration of the principle of the measuring procedure).

Echoes can usually also be received from adjacent distance sensors due to the large distance sensor detection angles; these are known as cross echoes. These occur at the obstacle due to scattered reflection. With the help of the triangulation method, the distance from the vehicle to an obstacle can be calculated from two echo signals. The propagation times of the signals from the direct measurement and from the cross measurement are required for this method. A long signal propagation time therefore corresponds to a large distance, and a short signal propagation time corresponds to a short distance to the obstacle.

Illustration of the principle for measuring procedure 

G12938162Courtesy of MERCEDES-BENZ USA

Display with detected obstacle 

If the environment monitoring system is not switched on and an obstacle is detected in the vehicle's path, a pop-up window appears in the multimedia display at speeds up to 10 km/h.

G12938163Courtesy of MERCEDES-BENZ USA

Environment monitoring while reversing 

During reverse travel the areas in front of and behind the vehicle are monitored. When the speed drops below the limit speed of 10 km/h, the environment monitoring system changes to measuring mode. If objects are detected in front of or behind the vehicle, the driver is warned by the lighting of the warning segments in the multimedia display and by a warning tone.

When the speed exceeds the limit speed of 12 km/h, the environment monitoring system switches back to standby mode.

If a trailer is detected (vehicles with trailer hitch) (electrical connection established between the vehicle and a trailer), the environment monitoring system is deactivated at the rear.

Environment monitoring in forward travel 

When driving forwards the area in front of the vehicle is monitored. When the speed drops below the limit speed of 10 km/h, the environment monitoring system changes to measuring mode. If obstacles are detected in front of or behind the vehicle, the driver is warned by the lighting of the warning segments in the multimedia display and by a warning tone.

When the speed exceeds the limit speed of 12 km/h, the environment monitoring system switches back to standby mode.

Functional restrictions 

The environment monitoring system does not recognize the following obstacles:

  Function schematics     
  Monitor surroundings, function schematic Model 118, 167, 177, 247, 293 with code P44 (Parking package) Model 118, 167, 177, 247, 293 with code P47 (Parking package with 360-degree camera) Model 118, 167, 177, 247 with code 235 (Active Parking Assist with PARKTRONIC) PE54.65-P-2500-97A
  Control units     
  Parking system control unit, basic function   GF54.65-P-9890A 
  Components     
  Distance sensor, basic function   GF54.65-P-2001A