Models W/Single Airbag

Diagnosis Chart:

The diagnostic procedures used are designed to aid in finding and repairing SIR problems. Outlined below are the 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 THE "SIR DIAGNOSTIC SYSTEM CHECK."
The "SIR Diagnostic System Check" should be the starting p0int of any SIR diagnostics. The "SIR Diagnostic System Check" checks for proper "INFLATABLE RESTRAINT" warning lamp operation and checks for SIR diagnostic trouble codes.
B. REFER TO THE PROPER DIAGNOSTIC CHART AS DIRECTED BY THE "SIR DIAGNOSTIC SYSTEM CHECK."
The "SIR Diagnostic System Check" leads you to the correct chart to diagnose any SIR problems. Bypassing these procedures may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement.
C. REPEAT THE "SIR DIAGNOSTIC SYSTEM CHECK" AFTER ANY REPAIR OR DIAGNOSTIC PROCEDURES HAVE BEEN PERFORMED.
Performing the "SIR Diagnostic System Check" after all repair or diagnostic procedures assures that the repair has been made correctly and that no other conditions exist.
D. Refer to "Intermittents and Poor Connections" when checking for proper connections at a connector.

DESCRIPTION
When the ignition switch is first turned "ON," system voltage is applied through Fuse #7 to the DERM at the "IGNITION 1" input and through Fuse #6 to the DERM at the "SIR Indicator Low" and "SIR Indicator High" inputs. 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. The "INFLATABLE RESTRAINT" warning lamp should blink 7 to 9 times as the ignition is just turned "ON."
2. As the engine is "Cranked" the "INFLATABLE RESTRAINT" warning lamp should remain on steady. When the warning lamp does not respond use Chart E to diagnose the malfunction.
3. Improper "INFLATABLE RESTRAINT" warning lamp operation is indicated. This test determines a warning lamp "on condition or "off condition."
4. The "INFLATABLE RESTRAINT" warning lamp has completed the "Bulb Check" and goes out, indicating no current diagnostic trouble codes exist.
5. This determines whether a current diagnostic trouble code exists or a false diagnostic request condition is present.
6. The "INFLATABLE RESTRAINT" warning lamp has completed the "Bulb Check" and indicates current diagnostic trouble codes exist.
7. Record all diagnostic trouble codes (both history and current) onto the repair order.
8. If there are no diagnostic trouble codes (history or current) record this fact onto the repair order. No further diagnosis is required.
9. If the scan tool indicates that no SIR data is being received from the DERM, then the data link requires diagnosis.
10. Diagnostic trouble codes are displayed (history or current). The order that the diagnostic trouble codes are diagnosed is very important. Refer to the recommended charts.