Chart E Warning Lamp Flashes DTC 12

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

When the ignition switch is first turned "ON," Ignition 1 voltage is applied from the "GAGES" fuse to "Redundant Indicator Ignition 1," terminal "B2," and to the "AIR BAG" warning lamp which is connected to "SIR Indicator," terminal "B1." The "AIR BAG" fuse applies system voltage to the "Ignition 1" inputs, terminals "A9" and "A10." The DERM responds by flashing the "AIR BAG" warning lamp 7 times.

When the engine is being cranked, Ignition 1 voltage is applied from the "SIR CRANK SENSE" fuse 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 "AIR BAG" warning lamp being "ON" during cranking. After cranking, the DERM will flash the "AIR BAG" warning lamp 6 times.

This chart diagnoses the situation where, after "Bulb Check" (6 or 7 flashes), the "AIR BAG" warning lamp is "OFF" for one second and then begins to flash. The sequence is as follows: the lamp will flash once, pause for one second, then flash twice. After a three second pause the previous sequence may repeat or a new pattern may occur. This condition will continue as long as the ignition switch is "ON."

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks for a short to ground on the "Diagnostic Request" circuit. Since grounding of the "Diagnostic Request" circuit flashes DTC 12, this ground must be supplied by the DERM or the wiring.