AutoCodes – GMC – B3902 2015 GMC Sierra

B3902 2015 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 2015 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 252

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 2015 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 2015 GMC Sierra - Incorrect Immobilizer Identifier Received - AutoCodes.com — B3902 2015 GMC Sierra Code - Incorrect Immobilizer Identifier Received

What does this mean?

What are the Possible Causes of the DTC B3902 2015 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 2015 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 2015 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 2015 GMC Sierra code?

Need more information on how to fix the B3902 2015 GMC Sierra code? Get Access to Factory Service Manuals

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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 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code B3902 on a 2015 GMC Sierra?

- Common symptoms include the engine not starting, the vehicle going into theft mode, or the security light staying on.

2. What does the OBDII code B3902 "Incorrect Immobilizer Identifier Received" mean on a 2015 GMC Sierra?

- This code indicates a communication error between the vehicle's immobilizer system and the Engine Control Module (ECM).

3. What are possible causes of OBDII code B3902 on a 2015 GMC Sierra?

- Possible causes include a faulty immobilizer system, issues with the ECM, wiring problems, or a key fob communication error.

4. How can I diagnose the OBDII code B3902 on my 2015 GMC Sierra?

- Diagnosis involves checking the immobilizer system for faults, testing the ECM communication, inspecting wiring for damage, and ensuring the key fob is functioning correctly.

5. Can I still drive my 2015 GMC Sierra with OBDII code B3902 present?

- It is not recommended to drive the vehicle with this code present, as it may result in starting issues or the vehicle going into theft mode unexpectedly.

6. How can I reset or clear the OBDII code B3902 on my 2015 GMC Sierra?

- Clearing the code typically involves diagnosing and fixing the underlying issue triggering the code. Once the problem is resolved, the code can be cleared with an OBDII scanner.

7. Is it safe to attempt DIY repairs for OBDII code B3902 on a 2015 GMC Sierra?

- Unless you have experience working with immobilizer systems and ECMs, it is recommended to consult a professional mechanic for proper diagnosis and repair.

8. Can a low battery voltage trigger OBDII code B3902 on a 2015 GMC Sierra?

- Yes, low battery voltage can sometimes cause communication errors between the immobilizer system and the ECM, leading to the B3902 code.

9. Are there any known recalls or technical service bulletins related to OBDII code B3902 on a 2015 GMC Sierra?

- Check with your local GMC dealership or visit the manufacturer's website to see if there are any recalls or technical service bulletins related to this specific OBDII code.

10. How much can I expect to pay for professional repairs related to OBDII code B3902 on a 2015 GMC Sierra?

- Repair costs can vary depending on the exact cause of the issue, but it is advisable to budget for diagnostic fees and potential parts replacement, which could range from a few hundred to over a thousand dollars.