AutoCodes – GMC – B3978 2017 GMC Sierra

B3978 2017 GMC Sierra Code - Incorrect Environmental Identifier Received from Inflatable Restraint Sensing and Diagnostic 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 Inflatable Restraint Sensing and Diagnostic Module, Inflatable Restraint Sensing and Diagnostic Module harness is open or shorted, Inflatable Restraint Sensing and Diagnostic 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: B3978 2017 GMC Sierra indicates Incorrect Environmental Identifier Received from Inflatable Restraint Sensing and Diagnostic Module.
Common causes: Common causes include Faulty Inflatable Restraint Sensing and Diagnostic Module, Inflatable Restraint Sensing and Diagnostic Module harness is open or shorted, Inflatable Restraint Sensing and Diagnostic 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 230

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 B3978 2017 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 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 B3978 2017 GMC Sierra - Incorrect Environmental Identifier Received from Inflatable Restraint Sensing and Diagnostic Module - AutoCodes.com — B3978 2017 GMC Sierra Code - Incorrect Environmental Identifier Received from Inflatable Restraint Sensing and Diagnostic Module

What does this mean?

What are the Possible Causes of the DTC B3978 2017 GMC Sierra?

Faulty Inflatable Restraint Sensing and Diagnostic Module
Inflatable Restraint Sensing and Diagnostic Module harness is open or shorted
Inflatable Restraint Sensing and Diagnostic Module circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3978 2017 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 B3978 2017 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 B3978 2017 GMC Sierra 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 B3978 2017 GMC Sierra Code

1. What does the OBDII code B3978 mean on a 2017 GMC Sierra?

The code B3978 indicates that the Inflatable Restraint Sensing and Diagnostic Module (SDM) has received an incorrect environmental identifier, potentially causing issues with the airbag system.

2. What are the common symptoms of code B3978 in a 2017 GMC Sierra?

Symptoms may include the airbag warning light illuminating, the airbag system being disabled, or stored diagnostic trouble codes in the SDM.

3. What causes the B3978 code to appear in a 2017 GMC Sierra?

Common causes include incorrect programming of the SDM, a mismatch of control module configurations, faulty wiring, or a failed SDM.

4. Can I drive my 2017 GMC Sierra with the B3978 code active?

It is not recommended, as the airbag system may not function correctly in the event of a collision, compromising occupant safety.

5. How is the B3978 code diagnosed in a 2017 GMC Sierra?

A technician will use a scan tool to confirm the code, inspect the SDM and related wiring, and verify proper programming and environmental identifier settings.

6. Can a software update fix the B3978 code in a 2017 GMC Sierra?

Yes, if the issue is due to incorrect SDM programming or a software mismatch, a software update or reprogramming may resolve the problem.

7. What is an environmental identifier in relation to the B3978 code?

The environmental identifier is a configuration parameter used by the SDM to ensure compatibility with the vehicleâ€™s specific setup and components.

8. How much does it cost to fix the B3978 code on a 2017 GMC Sierra?

Repair costs can vary but typically range from $150 to $500 depending on whether reprogramming, wiring repairs, or SDM replacement is needed.

9. Can a faulty airbag sensor cause the B3978 code?

No, the B3978 code is specifically related to incorrect environmental identifiers and is not directly caused by a faulty airbag sensor.

10. Is the B3978 code common in GMC Sierra trucks?

It is not a common code but can occur if there has been a recent SDM replacement, reprogramming error, or issue with the vehicleâ€™s control module configuration.