B1451

DTC B1451

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 Descriptors
DTC B1451
- Manual Cut-off Switch Malfunction

Circuit/System Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform turn-on test to diagnose critical malfunctions within SDM itself.

The SDM continuously checks the disable switch position switch and circuit defect by letting the regular voltage flow through the disable switch circuit and verifying the current.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

An open or short in wiring between SDM and disable switch.

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 100 malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

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

Component Connector End Views (Connector Views)
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.

* The steering wheel coil module
* The SDM module
* The steering wheel coil module wiring harness connector
* The SDM wiring harness connector

1. Ignition OFF, disconnect the passenger disable switch connector.
2. Disconnect the SDM connector.
3. Test for less than 1 ohm between terminal 60 of SDM and terminal 3 of disable switch.

• If resistance is not as specified, repair the open or high resistance in the circuit.

4. Connect the SDM connector.
5. Ignition ON, check for 12.5 mA at terminal 3 of disable switch.

• If amperage is greater than specified, replace the disable switch.

• If amperage is less than specified, replace the SDM.

Repair Instructions

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

* Steering Wheel Inflatable Restraint Module Coil Replacement (Removal and Replacement)
* Steering Wheel Inflatable Restraint Module Replacement (Steering Wheel Inflatable Restraint Module Replacement)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming