Chart C Warning Lamp Comes "ON" Steady

CIRCUIT DESCRIPTION
When the ignition switch is first turned to "ON," system voltage is applied from Fuse C-22 to the DERM at the "SIR Indicator High" input, terminal "B9," and to the "INFL REST" indicator (located in the instrument cluster) which is connected to the "SIR Indicator Low," terminal "A1." Fuse C-23 applies system voltage to the

"Ignition 1" input, terminals "A3" and "B3." The DERM responds by flashing the "INFL REST" indicator 7 to 9 times.

When the engine is being cranked, system voltage is applied from Fuse C-21 to the DERM and the "Crank" input, terminal "B10." The DERM responds by grounding the "SIR Indicator Low" output until system voltage is removed from the "Crank" input. This results in the "INFL REST" indicator being illuminated steady during cranking.

After cranking, the DERM will again flash the "INFL REST" indicator 7 to 9 times.

TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. An open Fuse C-23 would result in a loss of "Ignition 1" voltage to the DERM. The DERM will respond by grounding the "SIR Indicator Low" output, terminal "A1," whenever the ignition switch is in "ON."
2. A disconnected DERM harness connector will cause the "INFL REST" indicator to illuminate steady via the shorting bar from terminal "A1" to terminal "B1".
3. This test checks for a short to ground in the "SIR indicator Low" CKT 358.
4. This test checks to see if a short to ground caused Fuse C-23 to open.
5. This test determines whether the short to ground is due to a short to ground in the "Ignition 1" CKT 1139, a faulty arming sensor or a faulty DERM.
6. This test checks for an open in the "Ignition 1" CKT 1139 and the junction connector.
7. This test determines whether the fault is due to a short to B+ in the "Crank" CKT 806 or a faulty DERM.