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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1417 (Supplemental Inflatable Restraint System) >> Diagnostic Information and Procedures >> Diagnostic System Check - SIR >> Test Description

Test Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. 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:  This step checks to see if the AIR BAG warning lamp flashes seven times and then turns off when the ignition key is turned ON.
  2. 2:  This step checks to see if the scan tool powers up.
  3. 3:  This step checks to see if the scan tool can communicate with the inflatable restraint sensing and diagnostic module (SDM).
  4. 4:  This step checks to see if there are any current or history diagnostic trouble codes (DTCs) present.
  5. 5:  This step checks to see if there are communication DTCs (U-codes) present.
  6. 6:  This step checks to see if DTC B1000 (ECU Malfunction) is present.
Diagnostic System Check - SIR

Step Action Yes No
  1. Note the AIR BAG warning lamp while turning the ignition switch ON.
  2. The AIR BAG warning lamp should turn OFF after flashing seven times.
Does the AIR BAG warning lamp flash seven times and then turn off?
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 inflatable restraint sensing and diagnostic module (SDM).
Does the scan tool communicate with the SDM?
Go to Step 4  Go to Scan Tool Does Not Communicate with Class 2 Device (W/O Immobilizer) or Scan Tool Does Not Communicate with Class 2 Device (W/Immobilizer) 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 DTC's which begin with a "U"? Go to Scan Tool Does Not Communicate with Class 2 Device (W/O Immobilizer) or Scan Tool Does Not Communicate with Class 2 Device (W/Immobilizer) 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