Initial Inspection

SIR Diagnostic System Check

CAUTION: If the vehicle interior has been exposed to extensive water intrusion such as water leaks, driving through high water, flooding, or other causes, the sensing and diagnostic module (SDM) and SDM connector may need to be replaced. With ignition OFF, inspect the area around the SDM, including the carpet. If any significant soaking or evidence of previous soaking is detected, the water must be removed, water damage repaired, and the SDM and the SDM connector must be replaced. Before attempting any of these repairs, the supplemental inflatable restraints (SIR) must be disabled. Refer to Disabling the Supplemental Inflatable Restraints (SIR) and Supplemental Inflatable Restraints (SIR) Description

The SIR Diagnostic System Check must always be the starting point for any SIR diagnosis. The Diagnostic System Check reveals diagnostic trouble codes (DTCs) through the use of scan tool.

The diagnostic procedures used are designed to find any repair SIR conditions. To get the best results, it is important to use the diagnostic charts and follow the sequence listed below.

1. Perform the SIR Diagnostic System Check, which reveal diagnostic trouble codes (DTCs) through the use of scan tool. It also checks for proper airbag indicator operation.
2. Refer to the proper diagnostic chart as directed by SIR Diagnostic System Check. Bypassing these procedures may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.
3. Repeat the SIR Diagnostic System Check after any repair or diagnostic procedures have been performed to ensure that the repair has been made correctly and that no other malfunction exists.

Circuit Description
When the ignition switch is first turned to ON, ignition voltage is supplied from airbag fuse to find the SDM at input terminal 26. The SDM responds by flashing the airbag indicator 7 times and then turning it OFF while the SDM performs tests on the SIR.

Diagnostic Aids
The order in which DTCs are diagnosed is very important. Failure to diagnose the DTCs in the order specified may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement.

Step 1 - 13:

Troubleshooting

WARNING:
- The sensing and the diagnosis module (SDM) can maintain sufficient voltage to deploy the airbags and pretensioners for 1 minute after the ignition is OFF and the fuse has been removed. If the airbags and pretensioners are not disconnected, do not begin service until 1 minute has been passed after disconnecting power to the SDM. Otherwise, injury could result.
- During service procedure, be very careful when handling the SDM. Never strike or jar the SDM. Never power the supplemental inflatable restraints (SIR) when the SDM is not rigidly attached to the vehicle. All SDM mounting bolts must be carefully tightened, and the arrow on the SDM must be point toward the front of the vehicle to ensure proper operation of the SIR. The SDM could be activated if it is powered when it is not rigidly attached to the vehicle, resulting in unexpected deployment and possible injury.