GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Century 🢒 Restraints 🢒 SIR 🢒 Diagnostic System Check - SIR

Caution: In order to avoid deploying the air bag when troubleshooting the SIR system, use only the equipment specified in this manual and the instructions given in this manual. Failure to use the specified equipment as instructed could cause air bag deployment, personal injury to you or someone else, or unnecessary SIR system repairs.

These diagnostic procedures will help you to find and repair SIR system malfunctions. For best results, use the diagnostic tables and follow the sequence listed below:

  1. Refer to the diagnostic table as directed by a diagnostic system check - SIR. The diagnostic tables will help you to diagnose any SIR system malfunction. Bypassing these procedures may result in the following:
    2. • Extended Diagnostic Time
    • Incorrect Diagnosis
    • Incorrect Parts Replacement
  2. Repeat a Diagnostic System Check - SIR after you perform any repair or diagnostic procedures. This will verify that you correctly performed the repair. This will also ensure that no other malfunctions exist.

Test Description

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

  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.

Step

Action

Yes

No

1

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

2

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

3

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

4

  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

5

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

6

Does the scan tool display DTC B1000?

Go to DTC B1000 in Body Control System

Go to Diagnostic Trouble Code (DTC) List