GM Service Manual Online
For 1990-2009 cars only

The scan tool provides the following capabilities:

    • Read the data list.
    • Read the current trouble codes and the history trouble codes.
    • After a repair is completed, clear the diagnostic trouble codes.

Before communicating with the SIR system, ensure the scan tool contains the latest software In order to use the scan tool, connect the scan tool to the Data Link Connector (DLC), and turn the ignition switch to the ON position. The scan tool reads serial data from the inflatable restraint Sensing and Diagnostic Module (SDM).The serial data comes from the SDM output terminal 1 to the DLC terminal 9.

The SIR Scan Tool Data List contains all restraint-related parameters that are available on the scan tool. The list is in alphabetical order.

Use the SIR Scan Tool Data List, only after the following conditions are met:

    • The Diagnostic System Check is completed.
    • No Diagnostic Trouble Codes (DTCs) are set.
    • The SIR Diagnostics indicate correct operation.

Compare the scan tool values from a system that operates correctly with the values from the SIR system that you are diagnosing. The SIR Scan Tool Data List presents the values of a system that operates correctly.

Important: Verify that the scan tool that you are using operates correctly. Use of a malfunctioning scan tool can result in misdiagnosis and in unnecessary parts replacement.

Only the parameters below are referenced in this service manual for use in diagnosis. If the values match the values of a system that operates correctly, refer to Testing for Intermittent Conditions and Poor Connections for diagnosis.

Scan Tool Parameter

Units Displayed

Typical Data Value

Ignition ON, Engine OFF, and Driver Seat Belt Buckled

ADS (Forward Discriminating Sensor)

Active/Inactive

Active

Coil Resistance

Ohms

0.5 ohms

Driver Bag Energy Reserve

Volts

22 V

Driver Resistance

Ohms

2.6 ohms

Driver Seat Belt

Buckled/Unbuckled

Buckled

Driver Senselo

Volts

2.5 V

Driver VDIF

Millivolts

4-10 mV

Ignition

Volts

12 V

Lamp Driver Feedback

Active/Inactive

Active

Passenger Bag Energy Reserve

Volts

22 V

Passenger Resistance

Ohms

2.2 ohms

Passenger Senselo

Volts

2.5 V

Passenger VDIF

Millivolts

4-10 mV

SIR System Type

-

Driver/Passenger

Warning Lamp Cycles

Cycles

0-125 Cycles

Warning Lamp Control

On/Off

Off