AutoCodes – Chevrolet – B3979 2017 Chevrolet Silverado

B3979 2017 Chevrolet Silverado 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 2017 Chevrolet Silverado 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.

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Code Popularity 296

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
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Code B3979 2017 Chevrolet Silverado 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 2017 Chevrolet Silverado - Incorrect Environmental Identifier Received from HVAC Control Module - AutoCodes.com — B3979 2017 Chevrolet Silverado Code - Incorrect Environmental Identifier Received from HVAC Control Module

What does this mean?

What are the Possible Causes of the DTC B3979 2017 Chevrolet Silverado?

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 2017 Chevrolet Silverado?

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 2017 Chevrolet Silverado 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 2017 Chevrolet Silverado 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 B3979 2017 Chevrolet Silverado Code

1. What does the OBDII code B3979 mean on a 2017 Chevrolet Silverado?

The code B3979 indicates that the HVAC control module has received an incorrect environmental identifier, which may affect climate control functionality.

2. What are the common symptoms of code B3979 on a 2017 Chevrolet Silverado?

Symptoms may include improper operation of the HVAC system, incorrect temperature control, or failure to switch between different climate modes.

3. What causes the B3979 code to appear on a 2017 Chevrolet Silverado?

This code is typically caused by software issues, communication errors between modules, a malfunctioning HVAC control module, or wiring problems.

4. How do I diagnose the B3979 code on my 2017 Chevrolet Silverado?

Use a scan tool to confirm the code, inspect the HVAC control module connections and wiring for damage, and check for any software updates available for the vehicle.

5. Can a faulty HVAC control module cause the B3979 code?

Yes, a faulty or malfunctioning HVAC control module is a common cause of this code.

6. Is the B3979 code related to the air conditioning system?

Yes, it can affect the air conditioning system as it is tied to the overall HVAC operation, including temperature regulation and airflow.

7. Can I clear the B3979 code without repairing the issue?

You can clear the code with a scan tool, but if the underlying issue is not fixed, the code will likely return.

8. Is the B3979 code a serious issue?

While it may not immediately affect drivability, it can compromise comfort and HVAC functionality, especially in extreme weather conditions.

9. How much does it cost to fix the B3979 code on a 2017 Chevrolet Silverado?

The repair cost varies depending on the cause, but it could range from $100 for simple wiring repairs to $500 or more if the HVAC control module needs replacement.

10. Can a software update resolve the B3979 code?

Yes, in some cases, a software update from the dealership can resolve communication issues and clear the code.