Supplemental Inflatable Restraints
DTC B1370
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using the diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
DTC Descriptor
DTC B1370 06
- Device Ignition 1 Circuit Short to Ground or Open
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. If an open or short to ground in this SDM ignition 1 circuit is detected, then DTC B1370 will set.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
The SDM detects a short to ground or an open in the ignition 1 voltage circuit for at least 10 seconds 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 End Views By Name)
Description and Operation
SIR System Description and Operation (SIR System)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Connector Repairs (Connector Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Testing
Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected.
* SDM
* SDM wiring harness
1. Ignition OFF, remove the AIRBAG/DISPLAY fuse.
2. Ignition ON, with a DMM, test for 9-16 V between the voltage supply side and ground.
• If not the specified range, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443 (Wiring Systems and Power Management).
3. Ignition OFF, disconnect the harness connector at the SDM.
4. Ignition OFF, disconnect the X4 harness connector at the Underhood Fuse Block.
5. Ignition OFF, test for less than 1 ohm between the ignition 1 voltage circuit terminal 32 and the underhood fuse block terminal K4 X4.
• If greater then the specified range, test the circuit for an open/high resistance.
6. Ignition ON, test for less than 1 volt between the ignition 1 voltage circuit terminal 32 and the underhood fuse block K4 X4.
• If greater then the specified value, test the circuit for a short to voltage.
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 (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning)for SDM replacement, setup, and programming