System Overview

System overview

Introduction

The Forward Sensing Module (FSM) is an electronic system that:
- warns and aids the driver to brake the vehicle in the event of an imminent collision
- warns the driver when he/she is about to leave the lane
- warns the driver when his/her driving pattern deteriorates.
Parts of the system also make up an addition to the existing cruise control.

The following functions are provided by the Forward Sensing Module (FSM):
- Collision warning; warns the driver of a possible collision with vehicles in front.
- Automatic braking; brakes the vehicle automatically when a collision is unavoidable.
- Brake support; aids the driver, when there is a collision risk, to brake the vehicle when the brake pedal is depressed.
- Distance check. A permanent light indication in the front windshield informs that the time distance to the vehicle ahead is less than the set time distance. This helps the driver to maintain the time distance to the vehicle ahead.
- Adaptive cruise control; maintains a time interval to the vehicle ahead when cruise control is activated.
- Lane Departure Warning; warns the driver if they are unintentionally about the leave their lane.
- Driver Alert Control; alerts and warns the driver that their attention, and therefore, their driving pattern, have deteriorated due to fatigue for example.

Control module





The most important task of the Forward Sensing Module (FSM) is to manage the functions for:
- Collision warning
- Automatic braking (in the event of an unavoidable collision)
- Brake support (in the event of a collision risk)
- Distance control
- Adaptive cruise control
- Lane Departure Warning
- Driver Alert Control
The control module is located behind a panel by the pedal assembly. The entire control module is removed from the vehicle at replacement.
The Forward Sensing Module (FSM) communicates both with directly connected components and with other control modules via CAN communication.
The control module checks activations and input and output signals using an integrated diagnostic system A diagnostic trouble code is generated if the control module detects a fault. In certain cases the control module replaces the faulty signal with a substitute value.
Any diagnostic trouble codes are stored in the relevant control module memory. The data can be read off using a diagnostic tool.
If the control module detects a malfunction, a diagnostic trouble code is registered inside the control module's internal memory. At the same time, a number of values are stored. These are frozen at the time the malfunction occurred. Depending on the severity of the malfunction, certain functions may be partially or completely disengaged. Diagnostic trouble codes and frozen values (extended diagnostic trouble code information) can be read off using diagnostic tools via the data link connector in the vehicle.
For further information, also see Signal specifications.

Signals
The table below summarizes the input signals to and output signals from the Forward Sensing Module (FSM). The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication. The illustration below displays the same information with the Volvo component designations.