GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2003 🢒 Alero 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Diagnostic System Check - SIR

Caution: Refer to SIR Special Tool Caution in the Preface section.

Caution: If the vehicle interior is exposed to moisture and becomes soaked up to the level of the sensing and diagnostic module (SDM), the SDM and SDM harness connector must be replaced. The SDM could be activated when powered, which could cause airbag deployment and result in personal injury.

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 the 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 the 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. This step checks to see if the scan tool is able to communicate with the inflatable restraint sensing and diagnostic module (SDM).

    2.

  2. This step checks to see if there are communication DTCs, or U-codes, present.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

Go to Scan Tool Does Not Power Up in Data Link Communications

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the SDM.

Does the scan tool communicate with the SDM?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

Select the SIR display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - SIR

4

Does the scan tool display any DTCs which begin with a "U"?

Go to Diagnostic Trouble Code (DTC) List in Data Link Communications

Go to Step 5

5

Does the scan tool display DTC B1000?

Go to DTC B1000 in Body Control System

Go to Diagnostic Trouble Code (DTC) List