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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1100 (Supplemental Inflatable Restraint System) >> Diagnostic Information and Procedures >> Diagnostic System Check - SIR >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 1:  Tests to see if the AIR BAG indicator flashes seven times when the ignition is turned ON. The AIR BAG indicator should turn OFF after flashing 7 times.
  2. 2:  Tests to see if the scan tool powers up.
  3. 3:  Tests to see if the scan tool can communicate with the inflatable restraint sensing and diagnostic module (SDM).
  4. 4:  Tests to see if there are current or history diagnostic trouble codes (DTCs) present.
  5. 5:  Tests to see if there are communication DTCs (U-codes) present.
  6. 6:  Tests to see if DTC B1000 (ECU Malfunction) is present.
Diagnostic System Check - SIR

Step Action Yes No
Note the AIR BAG indicator while turning ON the ignition.
Does the AIR BAG indicator flash 7 times?
Go to Step 2  Go to Symptoms - SIR 
Install a scan tool.
Does the scan tool power up?
Go to Step 3  Go to Scan Tool Does Not Power Up in Data Link Communications
Attempt to establish communication with the SDM.
Does the scan tool communicate with the SDM?
Go to Step 4  Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
  1. Use the scan tool to request the SIR diagnostic trouble code (DTC) display.
  2. Record the displayed DTC(s) on the repair order, specifying as current or history.
Does the scan tool display any current or history DTCs?
Go to Step 5  System OK
Does the scan tool display any DTCs which begin with a "U"? Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications Go to Step 6 
Does the scan tool display DTC B1000? Go to DTC B1000 in Body Control System Go to Diagnostic Trouble Code (DTC) List