Chart A2 History Code Diagnosis

Diagnosis Chart:

Electrical Chart:

DESCRIPTION
When the Ignition Switch is first turned "ON" system voltage is applied through Fuse #6 to the "SIR Indicator High" input (B9) and the "INFLATABLE RESTRAINT" warning lamp which is connected to "SIR Indicator Low" input (A 1). Fuse #7 also applies system voltage to the "IGNITION 1" inputs (A3 and B3). The DERM responds by blinking the "INFLATABLE RESTRAINT" warning lamp 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 warning lamp circuit until system voltage is removed from the "CRANK" input. This results in a steady "INFLATABLE RESTRAINT" warning lamp during cranking.

After cranking, the DERM again blinks the "INFLATABLE RESTRAINT" warning lamp 7 to 9 times.

NOTES ON FAULT TREE
1. Checks for intermittent short to system voltage in 36VLR wiring (circuit 236).
2. Checks for intermittent short to ground in either the 36 VLR wiring (circuit 236) or to the DERM supplied ground through the lamp driver.
3. Checks for intermittent open in 36VLR wiring (circuit 236).
4. Checks for intermittent open in Force Hi wiring (circuit 714) and for intermittent short from Force Low (circuit 688) to either the Sense Low (circuit 752) or to circuit 349.
5. Checks for intermittent open or short to ground in Sense Low wiring (circuit 752).
6. Checks for short to ground in deployment loop (circuits 347, 348, 349) or shorts to ground in diagnostic circuits (circuits 688, 714, 752 and 753).