Engine-CodesGMC – B3902 GMC

B3902 GMC Code - Incorrect Immobilizer Identifier Received

Quick Answer

The B3902 GMC code indicates that the vehicle's immobilizer system has received an incorrect identifier. Common causes include Faulty key fob or transponder, Issues with the immobilizer system module, Wiring or connection problems in the immobilizer system. 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 GMC indicates Incorrect Immobilizer Identifier Received.
Common causes
Common causes include Faulty key fob or transponder, Issues with the immobilizer system module, Wiring or connection problems in the immobilizer system.
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.
Table of contents Created and updated by William Orellana on Sep 15, 2024
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Code B3902 GMC Description

The B3902 GMC code indicates that the vehicle's immobilizer system has received an incorrect identifier. The immobilizer system is designed to prevent unauthorized access to the vehicle by requiring a specific code or signal to start the engine. When the system detects an incorrect identifier, it will trigger this code and prevent the engine from starting.

OBDII Code B3902 GMC - Incorrect Immobilizer Identifier Received
B3902 GMC Code - Incorrect Immobilizer Identifier Received

Common Causes of B3902 GMC

  1. Faulty key fob or transponder
  2. Issues with the immobilizer system module
  3. Wiring or connection problems in the immobilizer system
  4. Low battery voltage affecting the immobilizer system
  5. Aftermarket modifications interfering with the immobilizer system

Symptoms of B3902 GMC

  1. Engine cranks but does not start
  2. Immobilizer warning light illuminated on the dashboard
  3. Inability to start the engine even with a correct key
  4. Vehicle goes into anti-theft mode
  5. Loss of power to various electrical components

How to Fix B3902 GMC

  1. Check the key fob battery and replace if necessary
  2. Inspect the wiring and connections in the immobilizer system for any damage or corrosion
  3. Use a diagnostic scanner to reset the immobilizer system and reprogram any necessary codes
  4. Replace the immobilizer system module if it is found to be faulty
  5. Ensure that any aftermarket modifications are not interfering with the immobilizer system

Cost to Fix B3902 GMC

The cost of repairing an incorrect immobilizer identifier received code can vary depending on the specific cause of the issue. In general, the cost of parts for this repair can range from $50 to $300, with labor costs adding an additional $100 to $200. However, it's important to note that these are rough estimates, and actual costs may vary based on factors such as location, vehicle make and model, and the extent of the repairs needed. It's recommended to consult with a professional mechanic to get a more accurate cost estimate for your specific situation.

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Information for Specific GMC Models

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 GMC Code

1. What does the OBDII code B3902 mean for a GMC vehicle?

B3902 indicates that the immobilizer system has detected an incorrect identifier received from a key or related module, preventing the vehicle from starting.

2. What are the common symptoms of code B3902 in a GMC?

Symptoms include the engine not starting, the security light staying on or flashing, and possible intermittent starting issues.

3. What causes the B3902 code to appear in a GMC?

Common causes include a faulty key fob, a malfunctioning immobilizer module, damaged wiring, or interference in the communication between the key and the immobilizer system.

4. How can I fix the B3902 code on my GMC?

Fixes may involve reprogramming the key, replacing the key fob battery, checking and repairing wiring, or replacing a faulty immobilizer module.

5. Can a weak key fob battery trigger the B3902 code?

Yes, a weak or drained key fob battery can cause communication errors and trigger the B3902 code.

6. Is it safe to drive a GMC with the B3902 code?

No, since this code prevents the engine from starting, the vehicle will usually not be drivable until the issue is resolved.

7. How much does it cost to repair the B3902 code on a GMC?

Repair costs vary depending on the issue but can range from $50 for a key fob battery replacement to over $500 for programming or replacing the immobilizer module.

8. Do I need to go to a dealership to fix the B3902 code on my GMC?

While some repairs, like a key fob battery replacement, can be done yourself, reprogramming keys or replacing the immobilizer module often requires specialized tools available at a dealership or qualified locksmith.

9. Can B3902 be caused by interference from other electronic devices?

Yes, electronic interference or nearby strong signals can sometimes disrupt communication between the key and the immobilizer system, triggering the code.

10. How do I prevent the B3902 code from recurring?

To prevent recurrence, maintain your key fob by replacing the battery regularly, avoid physical damage to the key, and address any wiring or module issues promptly.

Discuss the causes and fixes for B3902 GMC OBDII Code

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