Function in event of a frontal collision

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Input And Output Signals In Event Of A Frontal Collision

Courtesy of VOLVO CARS OF NORTH AMERICA.

In the event of frontal collision a function called single point sensing is used. This means that the collision pulse is only registered in one specific location. This function is integrated in the supplemental restraint system module (SRS) (4/9) and is called a collision sensor. When the collision pulse is sufficiently large an activation signal (current pulse) is transmitted to the front airbags and/or the seat belt tensioners.

The driver (8/30, 8/61) and front passenger (8/31, 8/32) airbags are deployed. The seat belt tensioners front (8/33.8/34) and rear are activated (8/55, 8/56 and 8/62).

When the collision protection system has been activated a collision signal is transmitted from the supplemental restraint system module (SRS) (4/9) to the central electronic module (CEM) (4/56) and carphone module (PHM) (16/60) on a directly connected cable. These two control modules ensure that;

The central locking system is unlocked,
the fuel pump (FP) is switched off,
the interior lighting is lit,
the warning lamps are lit,
the collision pulse is registered and
an automatic alarm is sent to CSC (customer service center), and to Volvo On Call (Plus) if applicable.

The following applies to structure week 9815-9949:

The collision pulse is registered in the supplemental restraint system (SRS) module. When the collision pulse is registered, the system is locked. The system then initiates the following activations:

The SRS indicator lamp lights red
No diagnostic trouble codes (DTCs) can be stored in the supplemental restraint system (SRS) module.

A collision status signal is also sent to the carphone module (PHM) and rear electronic module (REM) (4/58) on the Control Area Network (CAN).

The following applies to structure week 9950-:

The collision pulse is registered in the supplemental restraint system (SRS) module. When the collision pulse is registered the system is not locked. This means that diagnostic trouble codes (DTCs) can be stored after a collision. The system lights the SRS indicator lamp.

A collision status signal is also sent to the carphone module (PHM) and rear electronic module (REM) (4/58) on the Control Area Network (CAN).