GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 HHR 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B1370

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  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

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Ignition 1

B1370  06

--

B1370 06

B1370 01

B1370 06

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

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  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.
    2. ⇒If not within the specific range, refer to DTC B1370.
  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.
    5. ⇒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.
    6. ⇒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.
    7. ⇒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 after completing the diagnostic procedure.

    •  SIR/SRS Wiring Repairs
    •  Control Module References for BCM and SDM replacement, setup, and programming