Supplemental Inflatable Restraint (SIR)

CIRCUIT DESCRIPTION
During the "Turn-ON Tests," the DERM monitors the voltage at the "36 VLR" output, terminal A2," before this circuit begins to charge. If the diode in the arming sensor connected to terminal 2" is shorted, "Ignition 1," voltage will be present at the "36 VLR" output as soon as the ignition switch is turned to "ON." If the DERM detects voltage for three ignition cycles in a row, History DTC 33 will be set.

TEST CONDITIONS
Tested once each ignition cycle during the "Turn-ON Tests."

FAILURE CONDITIONS
History DTC 33 will set if "Ignition 1" voltage at the "36 VLR" output, terminal "A2," is detected within the first 500 milliseconds after the ignition switch is turned to "ON," for three consecutive ignition cycles.

ACTION TAKEN
The DERM stores a History DTC 33.

CONDITIONS TO CLEAR
History DTC 33 will remain as a history DTC until all DTCs are cleared using TECH 1 diagnosis.

TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks to see if the DTC was set by short ignition cycles.
2. This test checks to see if the DERM set the DTC falsely.
3. This test determines whether the fault is due to a short to B+ in the "36 VLR" CKT 236 or a shorted diode in the arming sensor.