System Overview

System overview

SRS (supplemental restraint system)





Warning! The SRS (supplemental restraint system) in the S40/V40 is DC supplied. This means that ohm measurement of the wiring must not occur without the cable being removed from the relevant airbag/tensioner. Failure to do so may result in accidental deployment. This could result in serious injury or death.

The main role of SRS (Supplemental Restraint System) is to manage the functions for:
- seat belt tensioners
- side impact sensors
- side impact protection (SIPS) bags
- front driver and passenger airbags
- inflatable curtains
- SRS indication
- collision output signal
- collision registration.
The SRS control module is in the transmission tunnel, between the gear selector lever and the parking brake.
The Supplemental Restraint System Module (SRS) communicates with directly connected components. The control module checks the input and output signals through an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault. Any diagnostic trouble codes (DTCs) are stored in the control module memory. The data can be read off using VIDA. The Supplemental Restraint System Module (SRS) can process multiple collisions, frontal collisions and side impacts.
The control module function can be easily checked by switching on the ignition. The SRS indicator lamp in the combined instrument panel must light up when the key is in ignition positions II-III. The lamp goes out after approximately 5 seconds if no faults are detected. This means that the supplemental restraint system (SRS) is functioning correctly.
For further information, also see Signal specifications.
The document covers cars from model year 2000 and forward. The differences from the model years 1996-1999 are that inflatable curtains have been introduced and that the side impact protection (SIPS) bags have been integrated with the system.

Warning! The SRS (supplemental restraint system) in the S40/V40 is DC supplied. This means that ohm measurement of the wiring must not occur without the cable being removed from the relevant airbag/tensioner. Failure to do so may result in accidental deployment. This could result in serious injury or death.

Signals
The table below summarizes the input signals to and output signals from the Supplemental Restraint System Module (SRS). The illustration below displays the same information with the Volvo component designations.