Supplemental Inflatable Restraints

DTC B1370

Diagnostic Instructions

- Perform the Diagnostic System Check - Vehicle prior to using the 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/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 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.

Diagnostic Aids

A history DTC maybe caused by an intermittent short or open in the ignition 1 circuit.

Circuit/System Testing

Important:When removing connectors inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected:
- SDM
- SDM wiring harness

1. Ignition OFF, remove the AIR BAG fuse.
2. Ignition ON, verify a test lamp illuminates between the ignition supply side of the fuse and ground.
->If the test lamp does not illuminate, refer to DTC B1370-B1379, B1380-B1389, or B1440-B1443.
3. Ignition OFF, remove the SDM harness connector.
4. Ignition OFF, test for less than 1 ohm between the ignition 1 voltage circuit terminal 32 and the underhood fuse block terminal 50 X3.
->If greater than the specified range, test the circuit for an open/high resistance.
5. Ignition ON, test for less than 1 volt between the SDM harness connector ignition 1 voltage circuit terminal 32 and ground.
->If greater than the specified value, test the circuit for a short to voltage.
6. If all circuits test normal, reconnect all connectors, replace fuse, clear all DTCs. If DTC B1370 stays current, replace the SDM.