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 the DTCs after a repair is completed

Before attempting to communicate with the SIR system, ensure that the scan tool contains the latest software. Connect the scan tool to the data link connector (DLC) and turn the ignition switch to the RUN position. The scan tool reads the serial data sent from the inflatable restraint sensing and diagnostic module (SDM) serial data output terminal 5 to the DLC terminal 9. The following table shows the typical values of the data displays under the following conditions:

    • The ignition switch is in the RUN position.
    • The engine is OFF.
    • The driver seatbelt is buckled.

Data List

Description

Typical Value

Ignition

Ignition 1 power feed

12 V

Lamp Driver

Warning lamp control method (hard wired lamp)

Internal

Driver Resistance

Driver deployment loop resistance

2.6 ohms

Passenger Resistance

Passenger deployment loop resistance

2.2 ohms

Driver Senselo

Driver low terminal voltage

4.1 V

Passenger Senselo

Passenger low terminal voltage

4.1 V

Driver VDIF

Voltage difference between driver high and driver low terminals

4-8 mV

Passenger VDIF

Voltage difference between passenger high and passenger low terminals

4-8 mV

Warning Lamp ON

Continuous warning lamp ON time

0 - 182 Hrs

Warning Lamp Control

Warning lamp state commanded by the SDM (On/Off)

Off

Lamp Driver Feedback

Warning lamp state detected by the SDM (Active/Inactive)

Inactive

Warning Lamp Cycles

Ignition cycles of the current warning lamp state

0 - 125 Cycles

Driver Seatbelt

Driver seatbelt status (Buckled/Unbuckled)

Buckled