Part 1 of 2

Test B: Inflatable Restraint Warning Lamp Comes ON Steady (Part 1 Of 2):

Supplemental Inflatable Restraint (SIR):

OPERATION:
When the ignition switch is first turned "ON," "Ignition 1" voltage is applied from the "IGN" fuse 1D to "Redundant Indicator Ignition 1" terminal "B2" and to the "INFLATABLE RESTRAINT" warning lamp which is connected to "SIR Indicator," terminal "B1." The "AIR BAG" fuse 1C applies system voltage to the "Ignition 1" Inputs, terminals "A9" and "A10." The DERM responds by flashing the "INFLATABLE RESTRAINT" warning lamp 7 times. If "Ignition 1" is outside of the normal operating voltage range, the "INFLATABLE RESTRAINT" warning lamp will come "ON" solid with no DTCs set.

When the engine is being cranked, "Ignition 1" voltage is applied from the "CRANK" fuse 1A to the DERM at the "Crank" input. The DERM responds by grounding the "SIR Indicator" output until "Ignition 1" voltage is removed from the "Crank" input. This results in the "INFLATABLE RESTRAINT" warning lamp being "ON" during cranking.

After cranking, the DERM will flash the "INFLATABLE RESTRAINT" warning lamp 6 times.

POSSIBLE CAUSES:
Test Description: Number(S) below refer to circled number(S) on the diagnostic chart.
1. An open AIR BAG fuse would cause the "INFLATABLE RESTRAINT" warning lamp to come "ON" steady.
2. A disconnected DERM harness connector will cause the warning lamp to come "ON" steady via the shorting bar from terminal "A1" to terminal "B1."
3. This test checks for an open in the "Ground" circuitry to the DERM.
4. This test checks for an open in the "Ignition 1" circuitry to the DERM.
5. This test checks whether a short to ground caused the "AIR BAG" fuse to open.
6. This test determines whether the short to ground is due to a malfunctioning dual pole arming sensor or a short in the wiring.