Buick Regal: DTC B3055

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 B3055

No Transponder Modulation or No Transponder

For symptom byte information, refer to Symptom Byte List.

Circuit/System Description

Without BTM and/or ATH/ATS

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the key is energized by the exciter coil surrounding the ignition lock cylinder.

The transponder transmits a signal to the immobilizer control module. The immobilizer control module translates this signal to a serial data message which is sent to the body control module (BCM). The BCM then compares this value to a value stored in memory. If the value is correct, the BCM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the learned key code does not match or a transponder value is not received, the BCM will send the start disable password to the ECM.

With BTM and/or ATH/ATS

When a ignition key is inserted into the key pocket/slot and the ignition mode switch is pressed, the transponder embedded in the key is energized by the immobilizer antenna exciter coil. The transponder transmits a signal to the immobilizer control module. The immobilizer control module translates this signal to a serial data message which is sent to the body control module (BCM). The BCM then compares this value to a value stored in memory. If the value is correct, the BCM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the learned key code does not match or a transponder value is not received, the BCM will send the start disable password to the ECM.

Conditions for Running the DTC

Ignition is in the Accessory or Run position.

Conditions for Setting the DTC

The BCM is unable to measure the ignition key transponder value.

Action Taken When the DTC Sets

• Vehicle starting will be disabled.
• The security indicator will illuminate. A service message will be displayed in the driver information center.

Conditions for Clearing the DTC

• A current DTC will be cleared when the BCM detects a valid transponder value from the ignition key.
• A history DTC will be cleared after 100 malfunction-free ignition cycles.

Diagnostic Aids

• Because DTC B3055 may be caused by a malfunctioning vehicle key, it is necessary to have all available vehicle keys at the time of diagnosis. A possible scenario would be a customer leaving the vehicle with a spare key during the service visit, but the key which they use everyday, not the spare key, is the cause of the DTC. Not having all available keys in this instance would result in the customer concern not being duplicate or a misdiagnosis.
• Ensure that the immobilizer control module is properly installed and fully seated. An audible and/or tactile click will indicate that the immobilizer control module is fully seated. To ensure proper transponder communication, the key must be in a specific location in relation to the immobilizer control module. If the immobilizer control module is not fully seated, transponder communication may not occur and DTC B3055 will set.
• For vehicle without BTM and/or ATH/ATS, verify the customer is not attempting to turn the ignition with the vehicle key partially folded. To ensure proper transponder communication, the key must be in a specific location in relation to the immobilizer control module. Attempting to start the vehicle with the key in the ignition and partially folded will result in no transponder communication and DTC B3055 will set.

Reference Information

Schematic Reference

Immobilizer Wiring Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEW INDEX

Master Electrical Component List

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

Without BTM and/or ATH/ATS

1. Ignition ON.

2. Verify that DTC B1370, B1380, or B1441 is not set.

• If any of the DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• Go to next step: If none of the DTCs are set

3. Verify the scan tool body control module Accessory parameter changes between Active and Inactive when turning the ignition ON and OFF.

• If the parameter does not change

Refer to Vehicle Will Not Change Power Mode.

• Go to next step: If the parameter changes

4. Verify all available keys are correct for the vehicle. This can be accomplished by comparing the part number that is laser etched on the key to the part number listed in the parts catalog.

• If a key is not correct

Replace the appropriate key.

• Go to next step: If all keys are correct

5. Verify that DTC B3055 does not set while attempting to start the vehicle which each available key.

• If DTC B3055 sets when attempting to start the vehicle with only one of the available keys

Replace the appropriate key.

• If DTC B3055 sets when attempting to start the vehicle with all of the available keys

Replace the K89 Immobilizer Control Module.

• Go to next step: If DTC B3055 does not set

6. All OK.

With BTM and/or ATH/ATS

1. Ignition ON.

2. Verify that DTC B1370, B1380, or B1441 is not set.

• If any of the DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• Go to next step: If none of the DTCs are set

3. Verify the scan tool body control module Accessory parameter changes between Active and Inactive when turning the ignition ON and OFF.

• If the parameter does not change

Refer to Power Mode Mismatch.

• Go to next step: If the parameter changes

4. Verify all available keys are correct for the vehicle. This can be accomplished by comparing the part number that is laser etched on the key to the part number listed in the parts catalog.

• If a key is not correct

Replace the appropriate key.

• Go to next step: If all keys are correct

5. Remove the battery from each of the available vehicle keys.

6. Verify that DTC B3055 does not set while attempting to start the vehicle which each available key. To start the vehicle with the key battery removed, the key must be placed in the key pocket/slot.

• If DTC B3055 sets when attempting to start the vehicle with only one of the available keys

Replace the appropriate key.

• If DTC B3055 sets when attempting to start the vehicle with all of the available keys

Replace the K89 Immobilizer Control Module.

• Go to next step: If DTC B3055 does not set

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for immobilizer control module replacement, programming, and setup.

READ NEXT: