GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    â€¢ Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.
    â€¢ Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    â€¢  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

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.

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

    â€¢ The SDM commands the AIR BAG indicator ON.
    â€¢ The SDM determines its power mode from the serial data message and discards the ignition 1 input for the remainder of the ignition cycle.

Conditions for Clearing the DTC

    â€¢ The condition for setting the DTC no longer exists.
    â€¢ A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    â€¢  Circuit Testing
    â€¢  Testing for Intermittent Conditions and Poor Connections
    â€¢  Wiring Repairs
    â€¢  Connector Repairs

Scan Tool Reference

Control Module References 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.

   â€¢ SDM
   â€¢ SDM wiring harness

  1. Ignition ON, verify DTC B1370 is not set in any other control modules.
  2. ⇒If the DTC is set in any other control module, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443 .
  3. Ignition OFF, disconnect the harness connector at the SDM.
  4. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 32 and ground.
  5. ⇒If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open high resistance.
  6. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    â€¢  SIR/SRS Wiring Repairs
    â€¢  Control Module References for SDM replacement, setup, and programming