Components Description
SDM (SENSING AND DIAGNOSTIC MODULE)WARNING:
During service procedures, be very careful when handling a Sensing and Diagnostic Module (SDM).
Be sure to read "SERVICE PRECAUTIONS" and "HANDLING PRECAUTIONS" before starting to work and observe every precaution during work. Neglecting them may result in personal injury or undeployment of the air bag when necessary.
CAUTION: After detecting one time of such collision as to meet deployment condition, the SDM must not be used. Replace with new one. Refer to "Testing and Inspection / Procedures" when checking the SDM.
Sensing and Diagnostic Module (SDM) is designed to perform the following functions in air bag system:
Energy Reserve
SDM maintains Reserve energy supply to provide deployment energy after ignition voltage is lost in a frontal crash.
Frontal Crash Detection
SDM monitors vehicle velocity changes to detect frontal crashes which are severe enough to warrant deployment.
Air Bag Deployment
When a frontal crash of sufficient force is detected, SDM will cause enough current to flow through air bag (inflator) modules to deploy air bags.
Malfunction Detection
SDM performs diagnostic monitoring of air bag system electrical components and sets a diagnostic trouble code (DTC) when a malfunction is detected.
Malfunction Diagnosis
SDM displays air bag diagnostic trouble codes (DTCs) and system status information through the use of special tool (SUZUKI scan tool).
SDM with on-board diagnostic function provides air bag diagnostic trouble codes by flashing "AIR BAG" warning lamp when on-board diagnosis function is used.
"AIR BAG" Warning Lamp Control
The light is turned "ON" to warn the driver of occurrence of a trouble and made to flash to check burned bulb of "AIR BAG" warning lamp.
Communication with SUZUKI scan tool
DTC display or DTC clear.
In response to the output request from SUZUKI scan tool, DTC recorded in the memory, each initiator circuit resistance and ignition voltage as recognized by SDM at time of the output request are provided.
DRIVER AIR BAG (INFLATOR) MODULE
WARNING:
Never attempt to disassemble or repair driver air bag (inflator) module. If any abnormality is found, be sure to replace it with new one as an assembly.
When handling it, be sure to read "Service Precaution".
Driver air bag (inflator) module consists of inflatable bag, inflator and trim cover, and is mounted to the center of steering wheel.
Driver inflator consists of initiator, burst disk and inflator gas tank. When vehicle is in a frontal crash of sufficient force, SDM causes current to flow through driver deployment loop. Current passing through the initiator causes a chemical reaction to occur. This chemical reaction generates pressure, depressing a burst disk which releases stored gas rapidly inflating air bag.
When inflatable bag deploys, its expansion force causes trim cover to open.
Gas in the inflatable bag is let out through two exhaust holes in the back of bag at the right and left.
PASSENGER AIR BAG (INFLATOR) MODULE
WARNING:
Never attempt to disassemble or repair passenger air bag (inflator) module. If any abnormality is found, be sure to replace it with new one as an assembly.
When handling it, be sure to read "Service Precaution".
Passenger air bag (inflator) module consists of inflatable bag, inflator and trim cover, and is mounted above glove box in instrument panel on the passenger side.
Passenger inflator consists of initiator, burst disk and inflator gas tank.
When vehicle is in frontal crash of sufficient force, SDM causes current to flow through passenger deployment loop. Current passing through initiator causes a chemical reaction to occur. This chemical reaction generates pressure, depressing burst disk which releases stored gas rapidly inflating air bag.
Once deployment starts, expansion force of the inflatable bag forces trim cover and move up.
"AIR BAG" MONITOR COUPLER
"AIR BAG" monitor coupler has a diagnosis switch terminal and a ground terminal.
With these terminals being shorted, "AIR BAG" warning lamp flashes to indicate the diagnostic trouble code.
(For details of diagnostic trouble code. Refer to Trouble Code Description.)