Supplemental Inflatable Restraint (SIR)

Wiring Diagram:

CIRCUIT DESCRIPTION
During the "Turn-ON" tests, performed at the beginning of each ignition cycle, the DERM delays the charging of the "Driver 36 VLR" power supply. While the delay is active the DERM measures the voltage at the "Driver 36 VLR" terminal "A4" and "Driver Source Sense" terminal "A5." When the voltage measured at the "Driver 36 VLR" power supply indicates it is in a discharged state and the voltage measured at "Driver Source Sense" is a specified amount below "Ignition 1 voltage, DTC 34 is set.

DTC WILL SET WHEN
With the "Driver 36 VLR" power supply in a discharged state, the voltage measured at "Driver Source Sense" terminal "A5" is a specified amount below "Ignition 1" voltage and no "higher priority faults" are detected. This test is run once each ignition cycle during the "Turn-ON" tests while the "36 VLR Delay" is active.

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

DTC WILL CLEAR WHEN
With the "Driver 36 VLR" power supply in a discharged state, the voltage measured at "Driver Source Sense" terminal "A5" is within specified range of "Ignition 1" voltage. When neither the set nor clear conditions are met, the state of the diagnostic trouble code from the previous ignition cycle is used.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks whether a malfunction is occurring.
2. This test checks for an open in the arming sensor ignition feed circuit.
3. This test determines whether the malfunction is an open in the "Driver Source Sense" circuit or an open in the arming sensor.

DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by an improper connection at arming sensor terminal A" or "C," improper connection at DERM terminal "A5," open ignition feed to the arming sensor, open "Driver Source Sense" circuit or a malfunctioning arming sensor ignition diode. The test for this diagnostic trouble code is only run while the "AIR BAG" warning lamp is performing the bulb check. When a scan tool "Clear Codes" command is issued and the malfunction is still present, the DTC will not reappear until the ignition switch is turned "OFF" for at least two minutes with the entire SIR system connected and then the ignition switch is turned "ON."