Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When the ignition switch is first turned "ON" battery voltage is applied to the "AIR BAG" warning lamp and to the "Ignition 1" input terminals "A9" and "A10." The DERM responds by flashing the "AIR BAG" warning lamp seven times alternating between the primary and redundant lamp drivers. The DERM monitors the primary lamp driver output by comparing the output state at "SIR Indicator" terminal "B1" to the microprocessor commanded state. When "Ignition 1" is above a specified value and the output state does not match the commanded state of the primary lamp driver for 400 milliseconds DTC 61 is set.

DTC WILL SET WHEN
"Ignition 1" voltage is above a specified value and the output state at the "SIR Indicator" terminal "B1" does not match the commanded state of the primary lamp driver for 400 milliseconds during "Continuous Monitoring."

ACTION TAKEN
DERM attempts to turn "ON" the "AIR BAG" warning lamp using the redundant lamp driver and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN
The ignition switch is turned "OFF."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s on the diagnostic chart.
1. When the DERM is configured for a serial data controlled warning lamp (smart cluster) DTC 61 will set. Clearing SIR diagnostic trouble codes will reset the DERM allowing the lamp driver in the DERM to control the "AIR BAG" warning lamp.

DIAGNOSTIC AIDS
Refer to CHART B and CHART C to diagnose warning lamp circuit malfunctions.