Supplemental Inflatable Restraints
DTC B1370
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this 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 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 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, short to voltage, 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 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 switch is in the OFF position.
B1370 06
The SDM detects a short to ground or an open 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 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
* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
Diagnostic Aids
A history DTC maybe caused by an intermittent short or open in the ignition 1 circuit.
Reference Information
Schematic Reference
SIR Schematics ([1][2]Air Bag Systems)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
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 component/connector.
* SDM module
* SDM wiring harness connector
1. Ignition OFF, remove the AIR BAG fuse from the BCM fuse center. Ignition ON, engine OFF, test for 9-16 volts between the voltage supply side of the fuse and ground.
• If not within the specific range, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443 (Wiring Systems and Power Management).
2. Disconnect the SDM harness connector.
3. Disconnect the BCM harness connector X3.
4. Ignition OFF, test for less than 1 ohm between the BCM ignition 1 voltage circuit terminal D7 X3 and the SDM terminal 33.
• If greater then the specified range, test the circuit for an open/high resistance.
5. Test for infinite resistance between the SDM ignition 1 voltage circuit terminal 33 and ground.
• If less than the specified range, test the circuit for short to ground.
6. Ignition ON, test for less than 1 volt between the SDM ignition 1 voltage circuit terminal 33 and ground.
• If greater then the specified value, test the circuit for a short to voltage.
7. If all circuits test normal then replace the SDM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for BCM or SDM replacement, setup, and programming