AutoCodes – GMC – B3902 2018 GMC Sierra

B3902 2018 GMC Sierra Code - Incorrect Immobilizer Identifier Received

Quick Answer

When certain modules are programmed and configured during installation, the module learns a specific environment identifier which is unique to the vehicle. Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body Control Module circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B3902 2018 GMC Sierra indicates Incorrect Immobilizer Identifier Received.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body Control Module circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 250

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 16, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3902 2018 GMC Sierra 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. The Diagnostic Trouble Code (DTC) sets when the control module's environment identifier does not match the environment identifier stored by the BCM.

OBDII Code B3902 2018 GMC Sierra - Incorrect Immobilizer Identifier Received - AutoCodes.com — B3902 2018 GMC Sierra Code - Incorrect Immobilizer Identifier Received

What does this mean?

What are the Possible Causes of the DTC B3902 2018 GMC Sierra?

Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection

How to Fix the DTC B3902 2018 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3902 2018 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B3902 2018 GMC Sierra code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B3902 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code B3902 on a 2018 GMC Sierra?

The common symptoms include difficulty starting the vehicle, the engine stalling, and the ignition system not recognizing the key.

2. What does the OBDII code B3902 "Incorrect Immobilizer Identifier Received" mean on a 2018 GMC Sierra?

This code indicates a communication error between the vehicle's immobilizer system and the ignition system, leading to a failure in recognizing the correct key.

3. What are possible causes of OBDII code B3902 on a 2018 GMC Sierra?

Possible causes include a faulty immobilizer module, issues with the key fob, wiring problems, or a malfunctioning ignition switch.

4. How can I diagnose the OBDII code B3902 on a 2018 GMC Sierra?

Diagnosis involves using a diagnostic scanner to retrieve the specific error code, checking the immobilizer system for faults, inspecting the key fob, and testing the wiring connections.

5. Can OBDII code B3902 be reset on a 2018 GMC Sierra?

Yes, the code can be reset using an OBDII scanner after the underlying issue has been identified and resolved.

6. Is it safe to continue driving with OBDII code B3902 illuminated on a 2018 GMC Sierra?

It is not recommended to continue driving with this code illuminated, as it may lead to potential starting or stalling issues while driving.

7. How much does it typically cost to repair OBDII code B3902 on a 2018 GMC Sierra?

The cost of repair can vary depending on the specific cause of the issue, but it may range from a few hundred to a thousand dollars, including parts and labor.

8. Can I fix OBDII code B3902 on a 2018 GMC Sierra myself?

If you have experience with automotive diagnostics and repair, you may be able to address the issue yourself by checking the key fob, inspecting wiring, or replacing the immobilizer module if necessary.

9. Are there any preventive measures to avoid OBDII code B3902 on a 2018 GMC Sierra?

Regularly maintaining the key fob, ensuring proper wiring connections, and promptly addressing any warning signs can help prevent issues leading to this error code.

10. Will OBDII code B3902 cause the vehicle to fail an emissions test?

The presence of this code may indicate an issue with the immobilizer system, which is not directly related to emissions control. However, it is advisable to address and resolve the problem before undergoing an emissions test to avoid potential complications.