Chart B Warning Lamp Comes On Steady

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When the ignition switch is first turned "ON," "Ignition 1" voltage is applied from fuse 39 to "Redundant Indicator Ignition 1," terminal "A4," and to the "AIR BAG" warning lamp which is connected to "SIR Indicator," terminal "A9." Fuse 21 applies system voltage to the "Ignition 1" input, terminal "B9." The SDM responds by flashing the "AIR BAG" warning lamp seven times. If "Ignition 1" is outside of the normal operating voltage range, the "AIR BAG" warning lamp will come "ON" solid with no DTCs set.

When the engine is being cranked, "Ignition 1" voltage is applied from fuse 11 to the SDM at the "Crank" input. The SDM responds by grounding the "SIR Indicator" output until "Ignition 1" voltage is removed from the "Crank" input. This results in the "AIR BAG" warning lamp being "ON" during cranking.

After cranking, the SDM 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 fuse 21 would cause the "AIR BAG" warning lamp to come "ON" steady.
2. A disconnected SDM harness connector will cause the warning lamp to come "ON" steady via the shorting bar from terminal "A9" to terminal "A10" (ground).
3. mis test checks for an open in the ground circuit to the SDM.
4. This test checks for an open in the "Ignition 1" circuit to the SDM.
5. This test checks for a short from the "Crank" input circuit to B+.
6. This test checks for a short from the "SIR a Indicator" circuit to ground.
7. This test checks whether a short to ground cause a fuse 21 to open.
8. This test determines whether the short to ground is due to a short in the wiring.