Chart B Warning Lamp Comes On Steady

CIRCUIT DESCRIPTION
When the ignition switch is first turned "ON1,, "Ignition 1" voltage is applied from the "IGN" fuse to "Redundant Indicator Ignition 1," terminal "B2" and to the "AIR BAG" warning lamp which is connected to "SIR Indicator," terminal "B1". The "SIR" fuse applies system voltage to the "Ignition 1" inputs, terminals "A9" and "A10". The DERM responds by flashing the "AIR BAG" warning lamp seven times. If "Ignition 1" voltage to the DERM is outside the normal operating range, the "AIR BAG" warning lamp will come "ON" solid with no DTC's set.

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

After cranking, the DERM will flash the "AIR BAG" warning lamp six times.

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. An open "SIR" fuse would cause the "AIR BAG" 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 for a short from the "SIR Indicator" circuit to ground
6. This test checks for a short from the "Crank" input circuit to B+.
7. This test checks whether a short to ground caused the "SIR" fuse to open.
8. This test determines whether the short to ground is due to a malfunctioning dual pole arming sensor or a short in the wiring.