Supplemental Inflatable Restraints
DTC B1370
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC B1370 01
- Device Ignition 1 Circuit Short to Battery
DTC B1370 06
- Device Ignition 1 Circuit Short to Ground or Open
Diagnostic Fault Information
Circuit/System Description
The inflatable restraint sensing and diagnostic module (SDM) monitors the ignition 1 signal from the ignition switch. When the vehicle ignition switch is placed in the RUN or CRANK position the switch supplies voltage to the SDM ignition 1 input terminal.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
The following conditions exist for at least 10 seconds:
B1370 01
The SDM detects a short to battery in the ignition 1 voltage circuit when the ignition switch is in the OFF position.
B1370 06
The SDM detects a short to ground or an open/high resistance in the ignition 1 voltage circuit when the ignition switch is in RUN or CRANK.
Action Taken When the DTC Sets
* The SDM commands the AIR BAG indicator ON via GMLAN serial data.
* The SDM stores DTC to memory.
* The SDM determines its power mode only from the GMLAN power mode messages and discards the ignition 1 input for the remainder of the ignition cycle.
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
Reference Information
Schematic Reference
SIR Schematics ([1][2]Air Bag Systems)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
SIR System Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
* The SDM module
* The SDM wiring harness connector
1. Ignition OFF, disconnect the AIRBAG fuse at the body control module (BCM).
2. Ignition ON, test for 9.0-16.0 volts on the supply voltage side of the AIRBAG fuse to ground.
• If not within the specified range, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443 (B1370).
3. Ignition OFF, reconnect the AIRBAG fuse and disconnect the X1 harness connector at the SDM.
4. Connect a test lamp between the ignition circuit terminal 2 and ground.
5. Command the ignition ON and OFF by using the ignition switch, the test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the BCM
• If the test lamp is always OFF, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM
6. If all circuits test normal, replace the SDM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* SIR/SRS Wiring Repairs (Component Tests and General Diagnostics)
* Control Module References (Programming and Relearning) for BCM and SDM replacement, setup, and programming