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 Descriptors
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 voltage 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 requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
* 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 condition for setting the DTC no longer exists.
* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.
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 Testing
Important: When removing the connectors inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector:
* SDM module
* SDM wiring harness connector
1. Ignition OFF, remove the IGN 1 AIR BAG fuse at the body control module (BCM).
2. Ignition ON, with a DMM, test for 9-16 volts between the voltage supply side of the AIR BAG fuse and ground.
• If not the specified range, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443 (B1370).
3. Ignition OFF, disconnect the harness connector at the SDM.
4. Ignition OFF, test for infinite resistance between the ignition 1 voltage circuit terminal 33 and ground.
• If not the specified value, test the B+ circuit for a short to ground.
5. Ignition ON, test for less than 1 volt between the ignition 1 voltage circuit terminal 33 and ground.
• If greater than the specified range, test the B+ circuit for a short to voltage.
6. Ignition OFF, test for less than 1 ohm between the ignition 1 voltage circuit terminal 33 and the AIR BAG fuse terminal A6 X3 at the BCM.
• If greater than the specified range, test the B+ circuit for an open/high resistance.
7. 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