Supplemental Inflatable Restraints

DTC B1370

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using the 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 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. 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 commands the AIR BAG indicator ON.
* 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)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
* Connector 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 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 IGN 1 AIR BAG fuse.
2. Ignition ON, test for 9-16V between the voltage supply side of the fuse and ground.

• If not within the specified range, Refer to DTC B1370 (B1370) .

3. Ignition OFF, disconnect the harness connector at the SDM and disconnect the X2 harness connector at the IP fuse block.
4. Ignition OFF, test for less then 1 ohm between the ignition 1 circuit terminal 32 at the SDM harness connector and the IP fuse block terminal 10 X2.

• If greater then the specified range, test the circuit for an open/high resistance.

5. Ignition ON, test for less then 1 volt between the ignition 1 circuit terminal 32 at the SDM harness connector and the IP fuse block terminal 10 X2.

• If greater then the specified value, test the circuit for a short to voltage.

6. If all circuits test normal, replace the SDM.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming
* SIR/SRS Wiring Repairs (Component Tests and General Diagnostics)