B1409

DTC B1409

Diagnostic Instructions

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

DTC Descriptor
DTC B1409
- Left Front Side Impact Sensor Invalid Serial Data Received

Diagnostic Fault Information





Circuit/System Description

The side impact sensor utilizes a unidirectional 2-wire circuit. The side impact sensor modulates current on the interface to send ID, state of health (SOH), and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the side impact sensor. When the ignition is turned ON and input power from the SDM is first detected, the side impact sensor responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The side impact sensor continually communicates status messages to the SDM, which determines if a fault is present in the side impact sensor circuit. When a fault is detected, the SDM resets the side impact sensor twice by removing and reapplying power to it. If the fault is still present, the SDM will set a DTC.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

A communication error occurs between the SDM and the left front side impact sensor.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
* A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

SIR Schematics (without WHB) (SIR Schematics (without WHB))SIR Schematics (WHB) (SIR Schematics (WHB))
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Circuit/System Testing

Note: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

* Left front side impact sensor
* SDM
* Left front side impact sensor wiring harness connector
* SDM wiring harness connector

1. Ignition ON, use the scan tool as clear SIR codes then recheck for DTCs.

• If DTC B1409 is set current, replace the left front side impact sensor.

2. Reconnect all SIR components. Ignition ON, use the scan tool to clear the DTCs then recheck for DTCs. Verify no DTCs are set.

• If DTC B1409 is current, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Inflatable Restraint Side Impact Sensor Replacement (Inflatable Restraint Side Impact Sensor Replacement)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming