B389A

DTC B389A

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this 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 B389A
- Environment Identification (Received by BCM)

Circuit/System Description

When certain modules are programmed and configured during installation, the module learns a specific immobilizer identifier which is unique to the vehicle. The immobilizer identifier is used to prevent swapping modules between vehicles. The body control module (BCM) is the keeper of the environment identifier. The instrument cluster (IPC), electronic brake control module (EBCM), HVAC control module, sensing diagnostic module (SDM), engine control module (ECM) and steering column lock control module (SCLM, if equipped) each learn the immobilizer identifier during their configuration process. During vehicle operation, each of these modules compare their immobilizer identifier to the BCM. If the identifiers match, vehicle starting is allowed. If an immobilizer identifier does not match, vehicle starting is disabled.

Conditions for Running the DTC

Ignition is in the ACCESSORY or RUN position.

Conditions for Setting the DTC

An incorrect environment identifier is received by the BCM.

Action Taken When the DTC Sets

* The security indicator in the instrument cluster will illuminate.
* Vehicle starting will be disabled.

Conditions for Clearing the DTC

A current DTC will be cleared when the module learns an environment identifier.

Reference Information
Description and Operation

Immobilizer Description and Operation (Immobilizer Description and Operation)
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)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

Note: Make sure to fix DTC B3902 first that has set in the following modules, IPC, SDM, ECM, HVAC, EBCM and SCLM (if equipped) before proceeding to the following diagnosis regarding the BCM.

Perform the Programming and Setup procedure for the BCM. Verify the DTC does not reset after programming.

If the DTC resets, replace the BCM.

Repair Instructions

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

Control Module References (Programming and Relearning)for instrument cluster, body control module and electronic brake control module replacement, programming and setup