Rear End Collision Warning System, Basic Function - GF91.40-P-1002A

MODEL ALL (CAR) with CODE 23P (Driving Assistance package) 

MODEL ALL (CAR) with CODE P20 (Driving Assistance package Plus) 

Overview 

This document contains the following information:

• General 
• Function requirements 
• Collision warning system escalation stages 

General 

The rear collision warning system is an expansion of the preventative occupant protection system and also takes into account hazardous situations that are caused by the following vehicle (rear impact). The traffic situation to the rear of one's own vehicle is detected by radar sensors at the rear area of the vehicle. The rear collision warning system analyzes the radar sensor system information and calculates the closing speed of the following vehicle as well as its distance to your vehicle. In the case of an imminent rear impact, the system warns the following vehicle and initiates different preventative passenger protection measures. Possible accident consequences for the vehicle occupants can thus be reduced.

Function requirements 

• Engine running or drive train operational
• No trailer on vehicle (vehicles with trailer hitch)

Collision warning system escalation stages 

1. The rear end collision warning system warns the traffic following behind in the event of an imminent rear impact. The rear hazard warning lamps is activated with a high flashing frequency thereby attracting the attention of the traffic following behind.
2. In the event of an ongoing collision hazard, preventive occupant protection measures are activated, including automatic seat belt tensioning.
3. If the driver's own vehicle is at a standstill during the hazard situation, the brake pressure of the service brake is increased. Braking hard significantly reduces the occupant load (whiplash injury) through the forward motion and it can help to avoid any subsequent collisions.

After a rear impact, the system is not available until it is enabled again using the diagnostic tester.

	Function schematics
	Rear end collision warning system, function schematic	Model 167, 177 with code 23P (Driving Assistance package) Model 167 with code P20 (Driving Assistance package Plus)	PE91.40-P-2502-97A
	Further basic functions
	Brakes, basic function		GF42.00-P-9900A
	Traffic area monitoring, basic function		GF54.71-P-1000A
	Actuate turn signal light, basic function		GF82.10-P-1023A
	Control units
	Intelligent driving control unit, basic function		GF30.30-P-9890A
	Electronic Stability Program control unit, basic function		GF42.45-P-9890A
	Components
	Intelligent driving radar sensor, basic function		GF54.71-P-2005A