AutoCodes – Chevrolet – B3979 Chevrolet

B3979 Chevrolet Code - Incorrect Environmental Identifier Received from HVAC Control Module

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 Heating, Ventilation, and Air Conditioning (HVAC) Control Module, HVAC Control Module harness is open or shorted, HVAC 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: B3979 Chevrolet indicates Incorrect Environmental Identifier Received from HVAC Control Module.
Common causes: Common causes include Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module, HVAC Control Module harness is open or shorted, HVAC 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 9,127

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 19, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B3979 Chevrolet 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 of control modules between vehicles. The Body Control Module (BCM) is the keeper of the environment identifier. The Instrument Cluster, Electronic Brake Control Module (EBCM), Heating, Ventilation, and Air Conditioning (HVAC) Control Module, Inflatable Restraint Sensing And Diagnostic Module, and Telematics Communication Interface Control Module 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.

OBDII Code B3979 Chevrolet - Incorrect Environmental Identifier Received from HVAC Control Module - AutoCodes.com — B3979 Chevrolet Code - Incorrect Environmental Identifier Received from HVAC Control Module

What does this mean?

What are the Possible Causes of the DTC B3979 Chevrolet?

Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
HVAC Control Module harness is open or shorted
HVAC Control Module circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3979 Chevrolet?

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 B3979 Chevrolet 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 B3979 Chevrolet code?

Need more information on how to fix the B3979 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3979 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

B3979 2014 Chevrolet Silverado — Incorrect Environmental Identifier Received from HVAC Control Module
B3979 2015 Chevrolet Silverado — Incorrect Environmental Identifier Received from HVAC Control Module
B3979 2016 Chevrolet Silverado — Incorrect Environmental Identifier Received from HVAC Control Module
B3979 2017 Chevrolet Silverado — Incorrect Environmental Identifier Received from HVAC Control Module
B3979 2018 Chevrolet Silverado — Incorrect Environmental Identifier Received from HVAC Control Module

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 B3979 Chevrolet Code

1. What are the common symptoms of OBDII code B3979 in a Chevrolet related to the HVAC control module?

- The common symptoms include incorrect environmental settings displayed on the HVAC control panel, inconsistent temperature regulation, and issues with the air conditioning system.

2. What can cause the OBDII code B3979 to trigger in a Chevrolet?

- The code B3979 is typically triggered when the HVAC control module receives an incorrect environmental identifier signal, often due to a malfunction in the module itself or a communication error.

3. How can I diagnose the root cause of OBDII code B3979 in my Chevrolet?

- A thorough diagnosis involves checking the wiring connections to the HVAC control module, testing the module for proper functionality, and verifying the signals being sent and received by the module.

4. Is it safe to continue driving my Chevrolet with OBDII code B3979 triggered?

- While the vehicle may still be operable, it is recommended to address the issue promptly to prevent further damage to the HVAC control system and ensure proper environmental control inside the vehicle.

5. Can I reset the OBDII code B3979 in my Chevrolet without fixing the underlying issue?

- Resetting the code without addressing the root cause may temporarily clear the error code, but it is likely to reappear until the underlying problem with the HVAC control module is resolved.

6. Are there any common DIY repair tips for fixing OBDII code B3979 in a Chevrolet?

- DIY repair tips include checking and cleaning the wiring connections to the HVAC control module, inspecting for any visible damage, and ensuring proper power supply to the module.

7. How much does it typically cost to repair OBDII code B3979 in a Chevrolet at a professional auto repair shop?

- Repair costs can vary depending on the extent of the issue, but the average cost to diagnose and repair OBDII code B3979 related to the HVAC control module in a Chevrolet ranges from $150 to $400.

8. Can extreme weather conditions or environmental factors trigger OBDII code B3979 in a Chevrolet?

- While extreme weather conditions can potentially affect the performance of the HVAC system, the code B3979 is more likely to be triggered by internal malfunctions or communication errors within the HVAC control module.

9. Is it possible to prevent OBDII code B3979 from occurring in my Chevrolet in the future?

- Regular maintenance of the HVAC system, including checking the wiring connections, keeping the module clean, and addressing any issues promptly, can help prevent the recurrence of code B3979 in the future.

10. Will fixing OBDII code B3979 improve the overall performance and efficiency of the HVAC system in my Chevrolet?

- Yes, addressing and resolving the underlying issues causing code B3979 can help restore proper functionality to the HVAC system, ensuring accurate environmental control and improving overall performance and efficiency.