Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
During normal, non-deployment operation of the SIR system, a small amount of current flows through the driver deployment loop. The diagnostic resistors within the arming sensor and the discriminating sensors along with the resistance of the inflator module cause voltage drops within the deployment loop. The DERM monitors the voltage at "Driver Side Low" terminal "B8" to detect shorts or opens within the driver deployment loop. When the measured voltage is above a specified percentage of "Driver 36 VLR" for 500 milliseconds DTC 23 is set.

DTC WILL SET WHEN
The voltage measured at "Driver Side Low" terminal "B8" is above a specified percentage of "Driver 36 VLR" for 500 milliseconds during "Continuous Monitoring" and DTC 35 is not set.

ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN
The voltage measured at Driver Side Low" terminal "B8" is within a specified percentage of "Driver 36 VLR" for 500 milliseconds during "Continuous Monitoring."

DTC TABLE TEST DESCRIPTION
Number(s) below refer to step number(s) on the diagnostic table.
1. The "SIR DIAGNOSTIC SYSTEM CHECK" should be the starting point for all diagnosis. SIR Diagnostic System Check
2. This test, essentially, determines whether the malfunction is due to a component or the wiring.
3. This test checks for a short from the "Driver 36 VLR" circuit to the "Driver Side Low" circuit.
5. This test checks for a short from the "Driver 36 VLR" circuit to the Driver Side High" circuit.
6. This test determines where the short from "Driver 36 VLR" circuit to the Driver Side High" circuit is located.
9. Refer to note at top of table.
10. Refer to note at top of table.
12. Refer to note at top of table,
13. This test checks for an open between the driver inflator module and the discriminating sensor network.
14. Refer to note at top of table.
16. This test determines where the open is located in CKT 348.
19. This test checks for an open in the RH forward discriminating sensor between terminal "A" and the splice.