DAB (Driver airbag) all consist of an inflator and cushion. The initiator (a gas generator igniting device) is part the inflator. When the vehicle is in a frontal or side crash of sufficient force to close the sensor of the SRSCM, current flows through the deployment loop. This current ignites the material and inflates the airbag.Driver Airbag (DAB) is installed in steering wheel and electrically connected to SRSCM via clockspring. It protects the driver from danger with deploying a bag when frontal crash occurs. The SRSCM determines deployment of Driver Airbag (DAB) by using the Front Impact Sensor (FIS) signal. The driver airbag is two stage devices. If the crash algorithm determines that only the first stage is to be activated, the second stage will be automatically disposed of after a programmable time in milliseconds has elapsed since the first stage deployment. The clock spring (coil spring) consists of two current carrying coils. It is attached between the steering column and the steering wheel. It allows rotation of the steering wheel while maintaining continuous contact of thedeployment loop through the inflator module.The steering wheel must be fitted correctly to the steering column with the clock spring at the neutral position, otherwise cable disconnection andother troubles may result. The SRS harness is wrapped in a yellow tube to be discriminated from other system harnesses. A shorting bar is included inside the wiring connectors of DAB, PAB, SAB and BPT inflator side. The shorting bar shorts the current flow the DAB, PAB, SAB and BPT module circuits when the connectors are disconnected. The circuits to the inflator module are shorted in this way to help prevent unwanted deployment of the airbag when servicing the airbag module.
The DAB squib circuit consists of the SRSCM, clock spring and DAB. If it causes the airbag to deploy when the airbag deployment conditions are satisfied. The above DTCs are recorded when the resistance too high is detected in the 2nd stage DAB squib circuit.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Check current
? Contact resistance in 2nd stage DAB circuit..
? Faulty Squib.
? Faulty clock spring.
? Faulty SRSCM.
Enable Conditions
? Ignition "ON"
Threshold Value
? 2nd stage DAB resistance = 6.0 ?
? Tolerance band : 4.1 ? < Rs < 6.0 ?
Diagnostic Time
Qualification
? More than 4 sec
De-Qualification
? More than 9.6 sec
? The SRS current measuring can be cause of component malfunction. So the current value is not mentioned in Threshold value to prohibit measuring the current.
? Tolerance band : It is unstable band that ECM detects the failure or not to do.
2nd stage DAB circuit resistance(O)
1.6 ? < Rs < 4.1 ?