B1620

DTC B1620

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 B1620
- Electronic Control Unit Performance

Circuit/System Description

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

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

The SDM does not implement diagnostic operation. In case of above, the wiring harness of SDM should be checked before replacing the SDM.

Action Taken When the DTC Sets

* The SDM commands ON the AIR BAG warning lamp via serial data communications.
* The SDM disables all deployments.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Reference Information
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 I/P module
* The SDM module
* The I/P wiring harness connector
* The SDM wiring harness connector

1. Ignition ON, use the scan tool to request SIR DTCs. Verify that DTC B1620 is set as current.

• If DTC B1620 was current replace the SDM.

2. Ignition ON, use the scan tool to clear the DTCs.

Repair Instructions

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

Control Module References (Programming and Relearning) for SDM replacement, setup, and programming