Diagnostic System Check

CAUTION:
- Refer to SIR Special Tool Caution in Service Precautions.
- 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.

These diagnostic procedures will help you to find and repair SIR system malfunctions. This service category also contains information for repairing SIR system malfunctions. For best results, use the diagnostic tables, and follow the sequence listed below:
1. Perform the A Diagnostic System Check - Restraint Systems. All SIR diagnostics must begin with the A Diagnostic System Check - Restraint Systems. The Diagnostic System Check - Restraint Systems determines the following results:
- Proper AIR BAG warning lamp operation
- Ability of the SDM to communicate through the data link connector (DLC)
- Existence of SIR current and/or history diagnostic trouble codes (DTC)
2. Refer to the diagnostic table as directed by the A Diagnostic System Check - Restraint Systems. The diagnostic tables will help enable you to diagnose any SIR system malfunction. Bypassing these procedures may result in the following problems:
- Extended diagnostic time
- Incorrect diagnosis
- Incorrect parts replacement Diagnostic Trouble Code Descriptions
3. Repeat the A Diagnostic System Check - Restraint Systems after you perform any repairs or diagnostic procedures. This will verify that you correctly performed the repair. This will also ensure that no other malfunctions exist.

Test Description

Steps 1 - 3:

Steps 4 - 6:

The numbers below refer to the step numbers on the diagnostic table.
1. This step checks to see if the AIR BAG warning lamp flashes seven times when the ignition key is turned ON.
2. This step checks to see if the scan tool powers up.
3. This step checks to see if the scan tool can communicate with the inflatable restraint sensing and diagnostic module (SDM).
4. This step checks to see if there are any current or history diagnostic trouble codes (DTCs) present.
5. This step checks to see if there are communication DTCs (U-codes) present.
6. This step checks to see if DTC B1000 (ECU Malfunction) is present.