CAUTION: In order to avoid deploying the air bag when troubleshooting the SRS system, use only the equipment specified in this manual and the instructions given in this manual. Failure to use the specified equipment as instructed could cause air bag deployment, personal injury to you or someone else, or unnecessary SRS system repairs.
Caution: If any water enters the vehicle's interior up to the level of the carpet
or higher and soaks the carpet, the sensing and diagnostic module (SDM) and
the SDM harness connector may need to be replaced. The SDM could be activated
when powered, which could cause deployment of the air bag(s) and result
in personal injury. Before attempting these procedures, the SRS system must
be disabled. Refer to Disabling the SRS System. With the ignition OFF, inspect
the SDM mounting area, including the carpet. If any significant soaking or
evidence of significant soaking is detected, you must perform the following
tasks:
Failure to follow these tasks could result in possible air bag deployment,
personal injury, or otherwise unneeded SRS system repairs.
These diagnostic procedures will help you to find and repair SRS system malfunctions. This service category also contains information for repairing SRS system malfunctions. For best results, use the diagnostic tables, and follow the sequence listed below:
• | Proper AIR BAG warning lamp operation |
• | Ability of the SDM to communicate through the data link connector (DLC) |
• | Existence of current and/or history diagnostic trouble codes (DTC) |
• | Extended Diagnostic Time |
• | Incorrect Diagnosis |
• | Incorrect Parts Replacement |
The ignition switch supplies Ignition 1 voltage to the inflatable restraint sensing and diagnostic module (SDM) at terminal A1 of the SDM connector C1 through the SDM Fuse. When the ignition switch is turned ON, the SDM responds by performing tests on the SRS system while the instrument cluster flashes the AIR BAG warning lamp seven times. Then, the SDM commands the instrument cluster to turn the AIR BAG warning lamp OFF through the Class 2 data circuit. If the SDM detects a malfunction, the SDM commands the instrument cluster to turn the AIR BAG warning lamp ON.
When an intermittent concern is indicated by a customer symptom that cannot be duplicated or by a diagnostic trouble code (DTC) that is retrieved as a history DTC without a corresponding current DTC, an intermittent condition may exist. Intermittent problems are usually caused by circuit or connector concerns. Refer to Testing for Electrical Intermittents and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
The numbers below refer to the step numbers on the diagnostic table.
This step checks to see if the AIR BAG warning lamp flashes seven times when the ignition key is turned ON.
This step checks to see if the scan tool powers up.
This step checks to see if the scan tool can communicate with the inflatable restraint sensing and diagnostic module (SDM).
This step checks to see if there are any current or history diagnostic trouble codes (DTCs) present.
This step checks to see if there are communication DTCs (U-codes) present.
This step checks to see if DTC B1000 (ECU Malfunction) is present.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Does the AIR BAG warning lamp flash seven times? | -- | Go to Symptoms | ||
Install a scan tool. Does the scan tool power up? | -- | Go to Scan Tool Does Not Power Up in Data Link Communications | ||
Attempt to establish communication with the inflatable restraint sensing and diagnostic module (SDM). Does the scan tool communicate with the SDM? | -- | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | ||
Does the scan tool display any current or history DTCs? | -- | System OK | ||
Does the scan tool display any DTC's which begin with a "U"? | -- | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | ||
Does the scan tool display DTC B1000? | -- | Go to DTC B1001 Option Configuration Error in Body Control System | Go to Diagnostic Trouble Code (DTC) List/Type |