Operation
The driver airbag (DAB) module, located in center of the steering wheel (as pictured above), contains a folded cushion and inflator unit. If the main circuit in the SRS control module senses an abnormal or higher force of impact than it is rated for, inflation of the cusion occurs. If battery voltage is too low or the power is disconnected due to the impact, the voltage regulator and the back-up power circuit, respectively, will keep voltage at a constant level.
Self-diagnosis System
A self-diagnosis circuit is built into the SRS control module, When the ignition switch is turned ON, the SRSCM indicator light turns on and turns off, after about six seconds, if the system is operating normally. If the light does not come If the light does not turn on or does not turn back off after six second, or if it lights while driving, an abnormality in the system is indicated. The system must be inspected and repaired as soon as possible. For bettery serviceability, the cause of the malfunction is stored in memory. The data link circuit passes the malfunction information from memory to the data link connector (DLC). This information can then be read with the scantool connected to the DLC (16P).
When short or decreased resistance in the driver’s airbag inflator. When the SRS warning light remain lite up and with DTC code, this means open circuit or increased resistance between control module and airbag harness.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | ● Driver airbag open or increased resistance | ● Poor contact in the connector or wiring harness. ● Short circuit in wiring harness. ● Short circuit in DAB squib. | |
Enable Conditions | ● Ignition "ON" | ||
Threshold Value | ● DAB Resistance ≤ 1 Ohm ( Less then 1Ω) | ||
Diagnostic Time | Qualification | ● More than 2 sec remaining | |
De-Qualification | ● More than10 sec remaining |
Test Condition | Resister (Ω) |
Ignition OFF | 1.9Ω ≤ R ≤ 5.7Ω |