B3979 GMC Code - Incorrect Environmental Identifier Received from HVAC Control Module
Quick Answer
The B3979 diagnostic trouble code (DTC) for GMC vehicles indicates that an incorrect environmental identifier was received from the HVAC (Heating, Ventilation, and Air Conditioning) control module. Common causes include Faulty HVAC control module, Wiring issues or loose connections, Communication error between modules. 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 GMC indicates Incorrect Environmental Identifier Received from HVAC Control Module.
- Common causes
- Common causes include Faulty HVAC control module, Wiring issues or loose connections, Communication error between modules.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code B3979 GMC Description
The B3979 diagnostic trouble code (DTC) for GMC vehicles indicates that an incorrect environmental identifier was received from the HVAC (Heating, Ventilation, and Air Conditioning) control module. In simpler terms, this means that there is a communication error between the HVAC control module and another component in the vehicle's system. The HVAC control module is responsible for managing the climate control functions within the vehicle, such as regulating the temperature, air distribution, and fan speed.
Common Causes of B3979 GMC
- Faulty HVAC control module
- Wiring issues or loose connections
- Communication error between modules
- Software glitch in the vehicle's computer system
Symptoms of B3979 GMC
- Inconsistent temperature output from the HVAC system
- Air distribution not matching selected settings
- HVAC system not responding to controls
- Check engine light illuminated on the dashboard
How to Fix B3979 GMC
- Perform a diagnostic scan to confirm the B3979 code and identify the specific cause of the issue.
- Inspect wiring connections and repair any damaged or loose wires.
- Test the HVAC control module for proper functionality and replace if necessary.
- Clear the DTC from the vehicle's computer system and perform a system reset if needed.
Cost to Fix B3979 GMC
The typical repair costs for addressing the B3979 DTC can range from $150 to $500, depending on the specific cause of the issue and the cost of replacement parts. This estimate includes both parts and labor. However, it is important to note that actual repair costs may vary based on factors such as the location of the auto repair shop, the make and model of the vehicle, and the type of engine. It's recommended to consult with a qualified mechanic for a more accurate cost estimate.
Need more information about the B3979 GMC code?
Need more information on how to fix the B3979 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B3979 GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- B3979 2014 GMC Sierra — Incorrect Environmental Identifier Received from HVAC Control Module
- B3979 2015 GMC Sierra — Incorrect Environmental Identifier Received from HVAC Control Module
- B3979 2016 GMC Sierra — Incorrect Environmental Identifier Received from HVAC Control Module
- B3979 2017 GMC Sierra — Incorrect Environmental Identifier Received from HVAC Control Module
- B3979 2018 GMC Sierra — Incorrect Environmental Identifier Received from HVAC Control Module
Frequently Asked Questions about B3979 GMC Code
1. What are common symptoms of OBDII code B3979 GMC?
- Common symptoms include incorrect temperature readings on the HVAC display, inconsistent heating or cooling performance, and the HVAC system not responding to temperature adjustments.
2. What does the OBDII code B3979 GMC indicate?
- The code indicates that the HVAC control module has received an incorrect environmental identifier, which can lead to issues with temperature control and system operation.
3. What are possible causes of OBDII code B3979 GMC?
- Possible causes include a faulty HVAC control module, wiring or communication issues between the HVAC control module and other vehicle systems, or a software glitch within the system.
4. How can I diagnose OBDII code B3979 GMC?
- Diagnosis typically involves using a diagnostic scanner to retrieve the code, checking the HVAC control module for any visible damage or loose connections, and testing the communication between the module and other components.
5. Can I repair OBDII code B3979 GMC myself?
- Depending on your level of automotive knowledge, you may be able to address this issue by checking and repairing any visible wiring issues, ensuring proper connections, or resetting the HVAC control module. However, complex repairs may require professional assistance.
6. Is it safe to continue driving with OBDII code B3979 GMC present?
- While the vehicle may still be operable with this code present, it is recommended to address the issue promptly to prevent further HVAC system malfunctions or potential damage.
7. How much does it typically cost to repair OBDII code B3979 GMC?
- The cost of repair can vary depending on the exact cause of the issue. Simple fixes like resetting the module or repairing wiring may be relatively inexpensive, while replacing a faulty HVAC control module can be more costly.
8. Can weather conditions affect the occurrence of OBDII code B3979 GMC?
- Extreme temperature fluctuations or exposure to moisture can potentially exacerbate issues related to this code, so it's important to keep the HVAC system well-maintained and protected from environmental factors.
9. Will resetting the OBDII code B3979 GMC make it go away permanently?
- Resetting the code may temporarily clear it, but if the underlying issue is not addressed, the code is likely to reappear. It's important to diagnose and fix the root cause to prevent ongoing problems.
10. How long does it usually take to repair OBDII code B3979 GMC?
- The repair time can vary depending on the complexity of the issue and the availability of parts. Simple fixes may take just a short amount of time, while more involved repairs could require several hours or more.
Discuss the causes and fixes for B3979 GMC OBDII Code
Code B3979 GMC comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.