AutoCodes – GMC – B1379 GMC

B1379 GMC Code - Ignition 3 Fault

Quick Answer

The Diagnostic Trouble Code (DTC) B1379 will set if IGNITION 3 is not active after IGNITION 1 has been active for 20 seconds. Common causes include Faulty Body Control Module (BCM), Body Control Module (BCM) harness is open or shorted, Body Control Module (BCM) 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: B1379 GMC indicates Ignition 3 Fault.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module (BCM) harness is open or shorted, Body Control Module (BCM) 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 750

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 Mar 19, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1379 GMC Description

The Diagnostic Trouble Code (DTC) B1379 will set if IGNITION 3 is not active after IGNITION 1 has been active for 20 seconds. When DTC is present, SERVICE VEHICLE SOON indicator illuminates and check gauges chime will sound. A current DTC B1379 will clear when the fault is no longer present and the ignition switch is cycled. A history DTC B1379 clears when module ignition cycle counter reaches reset threshold, without a repeat of malfunction.

OBDII Code B1379 GMC - Ignition 3 Fault - AutoCodes.com — B1379 GMC Code - Ignition 3 Fault

What does this mean?

What are the Possible Causes of the DTC B1379 GMC?

Faulty Body Control Module (BCM)
Body Control Module (BCM) harness is open or shorted
Body Control Module (BCM) circuit poor electrical connection
Faulty Instrument Panel Cluster (IPC)

How to Fix the DTC B1379 GMC?

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 B1379 GMC 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 B1379 GMC code?

Need more information on how to fix the B1379 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1379 GMC code diagnosed by a professional: Find a repair shop in your area

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 B1379 GMC Code

1. What are the common symptoms of OBDII code B1379 GMC (Ignition 3 Fault)?

The common symptoms include engine misfires, rough idling, difficulty starting the vehicle, and reduced engine performance.

2. What are the possible causes of the Ignition 3 Fault (B1379) code in a GMC vehicle?

Possible causes include faulty ignition coils, damaged spark plugs, wiring issues in the ignition system, or a malfunctioning ignition control module.

3. How can I diagnose the Ignition 3 Fault (B1379) code in my GMC vehicle?

To diagnose this code, you can use an OBDII scanner to read the error codes, visually inspect the ignition system components, test the ignition coils and spark plugs, and check the wiring for any damage or loose connections.

4. Can a bad battery cause the Ignition 3 Fault (B1379) code to appear?

Yes, a weak or faulty battery can cause voltage fluctuations that may trigger the Ignition 3 Fault code. It is recommended to check the battery and charging system as part of the diagnostic process.

5. How can I repair the Ignition 3 Fault (B1379) code in my GMC vehicle?

Repairing this code may involve replacing faulty ignition coils, spark plugs, or the ignition control module, repairing damaged wiring, or addressing any underlying issues causing the fault.

6. Is it safe to continue driving with the Ignition 3 Fault (B1379) code present?

It is not recommended to drive with the Ignition 3 Fault code present, as it can lead to engine performance issues and potential damage to other components. It is best to address the issue promptly.

7. Can a DIY enthusiast fix the Ignition 3 Fault (B1379) code, or should it be done by a professional mechanic?

Depending on your skill level and access to tools, a DIY enthusiast may be able to address the Ignition 3 Fault code by following repair guides and using proper diagnostic procedures. However, if you are unsure, it is best to consult a professional mechanic.

8. Will resetting the OBDII system clear the Ignition 3 Fault (B1379) code?

Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the fault is not addressed, the code is likely to reappear. It is important to diagnose and repair the root cause of the problem.

9. Can extreme weather conditions affect the appearance of the Ignition 3 Fault (B1379) code?

Extreme weather conditions, such as very high or low temperatures, can sometimes exacerbate existing issues in the ignition system and trigger the Ignition 3 Fault code. Ensuring your vehicle is properly maintained can help prevent such occurrences.

10. How much does it typically cost to repair the Ignition 3 Fault (B1379) code in a GMC vehicle?

The cost of repairing the Ignition 3 Fault code can vary depending on the specific cause of the issue, the labor rates in your area, and the parts needed for the repair. It is advisable to obtain quotes from reputable mechanics or repair shops for an accurate estimate.