Diagnostic Instructions
DTC Descriptor
DTC B3984
Device 1 Environment Identifier Not Programmable
For symptom byte information, refer to Symptom Byte List .
Circuit/System Description
When certain modules are programmed and configured during installation, the module learns a specific environment identifier which is unique to the vehicle. The environment identifier is used to prevent the swapping modules between vehicles. The body control module (BCM) is the keeper of the environment identifier. The instrument cluster, electronic brake control module, HVAC control module, inflatable restraint sensing and diagnostic module, engine control module (ECM), and steering column lock module (if equipped) each learn the environment identifier during their configuration process. During vehicle operation, the BCM sends the immobilizer identifier as a challenge and each module responds to the challenge by sending the environment identifier back to the BCM. If the BCM sends an incorrect immobilizer identifier or a specific number of incorrect environment identifiers are received, 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 programmed or no environment identifier is programmed.
Action Taken When the DTC Sets
Conditions for Clearing the DTC
A current DTC will be cleared when the module learns a correct environment identifier.
Reference Information
Schematic Reference
Immobilizer Schematics (Encore), Immobilizer Schematics (Trax)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX
Description and Operation
Immobilizer Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Replace the control module that set the DTC.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for instrument cluster, electronic brake control module, HVAC control module, inflatable restraint sensing and diagnostic module, engine control module, and steering column lock module replacement, programming, and setup.