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 and overview of each diagnostic category. |
DTC Descriptors
DTC B1370 01: Device Ignition 1 Circuit Short to BatteryDTC 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 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
| • | The SDM commands the AIR BAG indicator ON via serial data communications. |
| • | 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
Electrical Information Reference
Circuit/System Testing
- Ignition ON, use the scan tool checks for DTCs. Verify that DTC P2535 in the BCM does not set.
- 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 9-16 volts.
- Remove the SDM connector.
- 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.
- If all circuits test normal then replace the SDM.
Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
• The SDM module • The SDM wiring harness connector
| ⇒ | If DTC P2535 is current go to DTC P2535 . |
| ⇒ | If the voltage is less than 9-16 volts refer to DTC B1370 . |
| ⇒ | If any of the above conditions are found make the appropriate repair. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM and SDM replacement, setup, and programming |
