Chart C-1

Chart C1:

DERM Circuit:

DESCRIPTION:

When the Ignition switch is first turned "ON" system voltage is applied through fuse #18 to "SIR Indicator High" (B9) and to the "INFLATABLE RESTRAINT" Indicator Lamp which is connected to "SIR Indicator Low" (A1). Fuse #19 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. Checks if high side (power side) of the lamp circuit is fault free and if DERM ground is present. These circuits affect proper operation of the information center. If the information center is operative, then the power supply to the inflatable restraint indicator and DERM ground are not suspect.

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

3. Checks for short to system voltage (hot with ignition switch ON).

4. Determines if short to system voltage (hot with ignition switch ON) is internal to DERM.

5. Determines if open CKT is internal to DERM.