Models W/Dual Airbags

Diagnostic procedures used are designed to aid in finding and repairing SIR problems. Outlined below are steps to find and repair SIR problems quickly and effectively. Not carefully following these procedures may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement.
A. PERFORM "SIR DIAGNOSTIC SYSTEM CHECK."
The "SIR Diagnostic System Check" should be starting point of any SIR diagnostics. "SIR Diagnostic System Check" checks for proper "INFLATABLE RESTRAINT" warning lamp operation and checks for SIR diagnostic trouble codes.
B. REFER TO PROPER DIAGNOSTIC CHART AS DIRECTED BY "SIR DIAGNOSTIC SYSTEM CHECK."
The "SIR Diagnostic System Check" leads to correct chart to diagnose any SIR problems. Bypassing these procedures may result in extended diagnostic time, incorrect diagnosis and incorrect pans replacement.
C. REPEAT "SIR DIAGNOSTIC SYSTEM CHECK" AFTER ANY REPAIR OR DIAGNOSTIC PROCEDURES HAVE BEEN PERFORMED.

Performing "SIR Diagnostic System Check" after all repair or diagnostic procedures assures that repair has been made correctly and that no other conditions exist.

DESCRIPTION
When ignition switch is first turned "ON," system voltage is applied through "AIRBAG" fuse #7 to DERM at IGNITION 1" inputs and through fuse #6 to DERM's "SIR Indicator" output and "Redundant Indicator Ignition 1" input. DERM responds by blinking "INFLATABLE RESTRAINT" warning lamp 7 times.

When engine is being cranked, system voltage is applied to DERM's "CRANK" input. DERM grounds warning lamp circuit until system voltage is removed from "CRANK" input. This results in a steady "INFLATABLE RESTRAINT" warning lamp during cranking.

After cranking, DERM again blinks "INFLATABLE RESTRAINT" warning lamp 7 times, with solid "ON" of warning lamp during "CRANK" counting as one.

NOTES ON FAULT TREE
1. Improper "INFLATABLE RESTRAINT" warning lamp operation is indicated. This test quickly identifies a short to voltage in "SIR Indicator" wiring.
2. "INFLATABLE RESTRAINT" warning lamp should blink 7 times as ignition is just turned "ON."
3. As engine is "Cranked," "INFLATABLE RESTRAINT" warning lamp should remain on steady. When warning lamp does not respond use Chart E to diagnose malfunction.
4. "INFLATABLE RESTRAINT" warning lamp has completed "Bulb Check" and goes out, indicating no current diagnostic trouble codes exist.
5. Record all diagnostic trouble codes (both history and current) onto repair order.
6. Diagnostic trouble codes are displayed (history or current). Order that diagnostic trouble codes are diagnosed is very important. Refer to recommended charts.
7. Improper "INFLATABLE RESTRAINT" warning lamp operation is indicated. This test identifies an warning lamp "on condition."
8. Improper "INFLATABLE RESTRAINT" warning lamp operation is indicated. This test determines if fault is in redundant warning lamp circuits or if a warning lamp "off condition" exists.
9. This determines whether a current DTC exists or a false diagnostic request condition is present.
10. "INFLATABLE RESTRAINT" warning lamp has completed "Bulb Check" and indicates current diagnostic trouble codes exist.
11. If there are no diagnostic trouble codes (history or current) record this fact onto repair order. No further diagnosis is required.
12. If scan tool indicates that no SIR data is being received from DERM, then "Serial Data" circuit requires diagnosis.