Diagnostic System Check

DIAGNOSTIC SYSTEM CHECK

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.

The Diagnostic System Check - Restraint Systems must always be the starting point for any SIR diagnosis. The Diagnostic System Check reveals DTCs through the use of the 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 Diagnostic System Check - Restraint Systems, which reveals DTCs through the use of scan tool. It also checks for proper air bag indicator operation.
2. Refer to the proper diagnostic chart as directed by the Diagnostic System Check - Restraint Systems. Bypassing these procedures may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.
3. Repeat the Diagnostic System Check - Restraint Systems 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 the air bag fuse to find the sensing and diagnostic module (SDM) at the input terminal A1. The SDM responds by flashing the air bag 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.

Test

Steps 1-11:

Steps 12-16: