Chart C-1

Chart C1:

DERM Circuit:

DESCRIPTION:

When the Ignition switch is first turned "ON" system voltage is applied through fuse #1 to "SIR Indicator High" (B9) and to the "INFLATABLE RESTRAINT" Indicator Lamp which is connected to "SIR Indicator Low" (A1). Fuse #14 also applies system voltage to the "IGNITION 1" inputs (A3 and B3). The DERM responds by blinking the "INFLATABLE RESTRAINT" indicator 7 to 9 times.

When the engine is being cranked system voltage is applied to the DERM at the "CRANK" input. The DERM grounds the lamp circuit until system voltage is removed from the "CRANK" input. This results in a steady "INFLATABLE RESTRAINT" indicator during cranking.

After cranking the DERM will again blink the "INFLATABLE RESTRAINT" indicator 7 to 9 times if the Ignition Switch is "ON."

NOTES ON FAULT TREE:

1. Determines if DERM has lost its ground.

2. Determines if loss of DERM ground is in wiring harness or internal to DERM.

3. Checks if fuse #1 which feeds the "INFLATABLE RESTRAINT" indicator lamp is blown.

4. Determines if fault causing fuse #1 to blow is current.

5. Determines if fault causing fuse #1 to blow is in wiring harness or internal to DERM.

6. Checks if fuse block at fuse #1 receptacle has voltage.

7. Checks for short to system voltage (hot at all times).