GM Service Manual Online
For 1990-2009 cars only

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 B3900 00: No Immobiliser Identifier Learned

Circuit/System Description

When certain modules are programmed and configured during installation, the module learns a specific immobiliser identifier which is unique to the vehicle. The immobiliser identifier is used as a means to discourage vehicle theft by means of swapping modules between vehicles.

The steering column module (CIM) is the keeper of the immobiliser identifier. The instrument panel cluster (IPC), underhood electrical center (UEC), and rear electrical center (REC) each learn the immobiliser identifier during their configuration process. During vehicle operation, each of these modules report their immobiliser identifier to the CIM. The CIM compares the received immobiliser identifiers to its own stored identifier. If the identifiers match, vehicle starting is allowed. If two or more non--matching immobiliser identifiers are received by the CIM, vehicle starting is disabled.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

No immobiliser identifier is learned to the control module

Action Taken When the DTC Sets

    • Vehicle starting is disabled
    • The Service Vehicle Soon indicator will flash

Conditions for Clearing the DTC

    • A current DTC will be cleared when the module learns an immobiliser identifier.
    • A history DTC will clear after 100 malfunction free ignition cycles.

Reference Information

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

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

    Important: When reprogramming a control module which has already been programmed, additional security measures must be met before reprogramming is allowed. Prior to programming, security access must be granted by connecting a Tech 2 in a pass-thru arraignment and requesting security access in TIS. Once security access is granted, the security code must be entered. The security code can be found in DealerWorld. Both of these security measures must be met before the Reset ECU selection is allowed.

  1. Ignition ON, select Reset ECU on the scan tool for the appropriate control module.
  2. Perform the Programming and Setup procedure for the appropriate control module. Refer to Control Module References for programming and setup procedures. Verify the DTC does not reset after programming.
  3. If the DTC resets, replace the appropriate control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC, REC, or UEC replacement, programming, and setup