Side Impact Airbag Control Module (SIACM)

The content of this article reflects the changes called out by TSB 26-12-00.

SIDE IMPACT AIRBAG CONTROL MODULE

DESCRIPTION

Fig. 3:

Vehicles equipped with side impact airbags use two Side Impact Airbag Control Modules (SIACM). One is located on each respective side body B-pillar.

OPERATION
The impact sensor provides verification of the direction and severity of the side impact. The right side SIACM controls the right seat airbag. The left side SIACM controls the left seat airbag. In the event of a side impact the appropriate SIACM will send an electronic signal to its airbag, deploying the airbag. The SIACM communicates with the Occupant Restraint Controller (ORC) via the PCI bus circuit.

The accelerometer pulses are sent to a microprocessor, which contains a decision algorithm. When an impact is severe enough to require airbag protection, the SIACM microprocessor sends a signal to deploy the side airbag that completes the electrical circuits to the right or left side airbag. The sensor is calibrated for the specific vehicle and reacts to the severity and direction of the impact.