GM Service Manual Online
For 1990-2009 cars only

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

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Ignition 1 Circuit

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

    â€¢ The SDM commands the AIR BAG indicator ON via GMLAN serial data.
    â€¢ The SDM stores DTC to memory.
    â€¢ 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

    â€¢ A current DTC clears when the malfunction is no longer present.
    â€¢ 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

SIR Connector End Views

Electrical Information Reference

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

       â€¢ The SDM module
       â€¢ The SDM wiring harness connector

  1. Ignition ON, use the scan tool checks for DTCs. Verify that DTC  P2535 in the BCM does not set.
  2. ⇒If DTC P2535 is current go to DTC P2535 .
  3. Ignition OFF, remove the Air Bag fuse from the BCM fuse center. Ignition ON, engine OFF test the voltage side of the Air Bag fuse with a DMM. Measure the voltage of the Air Bag fuse voltage side and ground. The voltage should read 9.0-16.0 volts.
  4. ⇒If the voltage is less than 9.0-16.0 volts refer to DTC B1370 .
  5. Remove the SDM connector. Refer to SDM replacement in Repair Instructions for connector location.
  6. With the Air Bag fuse removed, test the ignition 1 voltage circuit between the BCM fuse center and the SDM for a short to voltage or an open. Verify that a short to voltage or an open does not exist.
  7. ⇒If any of the above conditions are found make the appropriate repair.
  8. If all circuits test normal then replace the SDM.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM and SDM replacement, setup, and programming