When the sensing and diagnostic module (SDM) detects any problem it illuminates the air bag warning indicator and stores the DTCs.

The supplemental inflatable restraints (SIR) diagnostic system check must be always the starting point for any SIR diagnosis. The diagnostic system check reveals DTCs through the use of the scan tool. It also checks for proper air bag warning lamp operation.

The 2 types of DTCs that may be recorded are as follows :

1. Active DTCs represent a malfunction being detected during the current ignition cycle. Active DTCs are stored in random access memory (RAM).
2. Historic DTCs represent malfunctions detected since the last time the historic memory was cleared. Historic DTCs are stored in the electrically erasable programmable read-only memory (EPROM).

Notice: Refer to Defective Scan Tool Notice in the Preface section.

North America

A scan tool can read serial data from terminal 9 of the data link connector (DLC). The scan tool is used to read DTCs, and to clear some DTCs after a repair is completed.

To use the scan tool, turn the ignition OFF, connect the scan tool to the DLC, and turn the ignition switch to ON.

Follow the instructions in the scan tool manual. The SDM sends serial data from terminal 9 of the SDM to terminal 13 of the DLC.

Except North America

A scan tool can read serial data from terminal 9 of the DLC. The scan tool is used to read DTCs, and to clear some DTCs after a repair is completed. By design, DTC 051 and 053 can not be cleared. And the DTC 061 can not be cleared for the ignition cycle once the DTC has been detected by the SDM.

To use the scan tool, turn the ignition OFF, connect the scan tool to the DLC, and turn the ignition switch to ON.

Follow the instructions in the scan tool manual. The SDM sends serial data from terminal A4 of the SDM to terminal 9 of the DLC.