SIR Diagnostic System Check

Diagnostic Chart:

The diagnostic procedures 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 point of any SIR diagnostics. The "SIR DIAGNOSTIC SYSTEM CHECK" checks for proper "INFLATABLE RESTRAINT" indicator operation and checks for SIR 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 REPAIRS 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.

NOTES ON FAULT TREE

1. Improper "INFLATABLE RESTRAINT" indicator operation is indicated. This test quickly identifies a short to voltage in the "SIR Indicator" wiring.

2. The "INFLATABLE RESTRAINT" indicator should flash 7 times as the ignition is just turned "ON".

3. As the engine is "cranked", the "INFLATABLE RESTRAINT" indicator should remain "ON" steady. When the indicator does not respond, use Chart 2 to diagnose the malfunction.

4. The "INFLATABLE RESTRAINT" indicator has completed the "Bulb Check" and goes out, indicating no current codes exist.

5. Checking if vehicle will enter diagnostics. If not, refer to "SELF-DIAGNOSTIC SYSTEM CHECK."

6. Codes are displayed (history or current). The order in which the codes are diagnosed is very important.

7. If there are no codes (history or current), record this fact on the repair order. No further diagnosis is required.

8. If On-Board Diagnostics indicate that no data is being received by the DERM, then refer to Code B333 "LOSS OF DERM DATA."

9. Improper "INFLATABLE RESTRAINT" indicator operation is indicated. This test identifies an indicator "on condition".

10. Improper "INFLATABLE RESTRAINT" indicator operation is indicated. This test determines if fault is in the redundant indicator circuits or if an indicator "off condition" exits.

11. Checking if "INFLATABLE RESTRAINT" indicator is "ON" with no codes set. If it is "ON" with no codes, replace DERM.