GM Service Manual Online
For 1990-2009 cars only

The scan tool used provides the following capabilities:

    • Read the data list.
    • Read current and history diagnostic trouble codes (DTCs).
    • Clear all DTCs after a repair is completed.

Make sure the scan tool contains updated software before attempting to communicate with the SIR system. To use the scan tool, connect it to the data link connector (DLC) and turn the ignition switch to the RUN position. The scan tool reads serial data sent from the inflatable restraint sensing and diagnostic module (SDM) serial data output terminal 12 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 arranged in the order as they appear on the scan tool.

Use the SIR Scan Tool Data List only after the following is determined:

    • Diagnostic System Check is completed.
    • No Diagnostic Trouble Codes (DTCs) are set.
    • SIR Diagnostics indicates functioning properly.

Scan tool values from a properly operating system may be used for comparison with the SIR system you are diagnosing. The SIR Scan Tool Data List represents values seen on a properly operating system.

Important: Make sure the scan tool that you are using is functioning properly. Use of a malfunctioning scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to Intermittents and Poor Connections for diagnosis.

SIR Scan Tool Data List

Scan Tool Parameter

Description

Typical Data Value

Ignition ON, Engine OFF, and Driver Seat Belt Buckled

Ignition

Ignition power feed

12 V

Driver Frontal Resist.

Driver frontal air bag deployment loop resistance

2.8 ohms

Pass. Frontal Resist.

Passenger frontal air bag deployment loop resistance

2.2 ohms

LH Side Air Bag Resist.

Driver side air bag deployment loop resistance

2.4 ohms

RH Side Air Bag Resist.

Passenger side air bag deployment loop resistance

2.4 ohms

LH Pretens. Resist.

Driver pretensioner deployment loop resistance

2.4 ohms

RH Pretens. Resist.

Passenger pretensioner deployment loop resistance

2.4 ohms

Driver Frontal Senselo

Driver frontal air bag low voltage

3.1 V

Pass. Frontal Senselo

Passenger frontal air bag low voltage

3.1 V

LH Side Air Bag Senselo

Driver side air bag low voltage

3.1 V

RH Side Air Bag Senselo

Passenger side air bag low voltage

3.1 V

LH Pretens. Senselo

Driver pretensioner low voltage

3.1 V

RH Pretens. Senselo

Passenger pretensioner low voltage

3.1 V

Driver Frontal VDIF

Driver frontal air bag deployment loop voltage difference

4-10 mV

Passenger Frontal VDIF

Passenger frontal air bag deployment loop voltage difference

4-10 mV

LH Side Air Bag VDIF

Driver side air bag deployment loop voltage difference

4-10 mV

RH Side Air Bag VDIF

Passenger side air bag deployment loop voltage difference

4-10 mV

LH Pretensioner VDIF

Driver pretensioner deployment loop voltage difference

4-10 mV

RH Pretensioner VDIF

Passenger pretensioner deployment loop voltage difference

4-10 mV

Warning Lamp On

Warning lamp state commanded

0-182 Hours

Warning Lamp Cycles

Number of ignition cycles with Warning Lamp On

0-125 Cycles

Driver Seatbelt

Buckled/Unbuckled

Buckled