Service Information

Cruze

DTC B3976

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B3976 00: Unconfigured Transponder

Circuit/System Description

When the body control module (BCM) is in the learn coded key state, the BCM checks the current key to ensure it has been configured as a proper vehicle key.

Conditions for Running the DTC

•	Ignition is in the Accessory or Run position.

•	The BCM is in the learn coded key state.

Conditions for Setting the DTC

The BCM has determined the current key is not configured as a proper vehicle key.

Action Taken When the DTC Sets

•	Vehicle starting will be disabled.

•	The security indicator in the instrument cluster will be illuminated. A service message will be displayed in the driver information centre.

Conditions for Clearing the DTC

•	A current DTC will be cleared when the BCM detects a properly configured vehicle key.

•	A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

While viewing DTCs with a scan tool, attempt to start the vehicle using all of the available keys. The vehicle should start with all available keys.

⇒	If any key results in inoperative starting and DTC B3976 is set as current, replace the appropriate key.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Replacing Keys