AutoCodes – GMC – B1439 2018 GMC Sierra

B1439 2018 GMC Sierra Code - Intermittent Device Voltage

Quick Answer

The vehicle control modules or sensors monitor the system voltage to verify the system voltage is within the normal operating range. Common causes include Low battery voltage, Faulty Control Module, Control Module harness is open or shorted. 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: B1439 2018 GMC Sierra indicates Intermittent Device Voltage.
Common causes: Common causes include Low battery voltage, Faulty Control Module, Control Module harness is open or shorted.
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 391

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 Jul 11, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1439 2018 GMC Sierra Description

The vehicle control modules or sensors monitor the system voltage to verify the system voltage is within the normal operating range. Damage to components, and incorrect data can occur when the voltage is out of range. The vehicle has multiple Control Modules that will set this Diagnostic Trouble Code (DTC).

OBDII Code B1439 2018 GMC Sierra - Intermittent Device Voltage - AutoCodes.com — B1439 2018 GMC Sierra Code - Intermittent Device Voltage

What does this mean?

What are the Possible Causes of the DTC B1439 2018 GMC Sierra?

Low battery voltage
Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC B1439 2018 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 B1439 2018 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 B1439 2018 GMC Sierra code?

Need more information on how to fix the B1439 2018 GMC Sierra code? Get Access to Factory Service Manuals

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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 B1439 2018 GMC Sierra Code

1. What does the OBDII code B1439 mean on a 2018 GMC Sierra?

B1439 indicates "Intermittent Device Voltage," meaning there's an irregular or unstable voltage detected in a specific device or circuit in the vehicle.

2. What are common symptoms of code B1439 on a 2018 GMC Sierra?

Symptoms can include a malfunctioning or unresponsive electronic component, intermittent functionality of certain systems, or warning lights on the dashboard.

3. What causes the B1439 code to appear in a 2018 GMC Sierra?

Common causes include loose or corroded electrical connections, a failing control module, a weak battery, or a faulty wiring harness.

4. Can a low battery trigger the B1439 code?

Yes, a weak or low battery can cause irregular device voltage and trigger the B1439 code.

5. How can I diagnose the B1439 code on my 2018 GMC Sierra?

Start by checking the battery's voltage and condition, inspect wiring and connections to the affected device, and use a scan tool to identify the specific system or module involved.

6. Is it safe to drive with the B1439 code active?

It depends on the system affected. If it involves critical safety features, such as airbags or braking systems, driving may not be safe.

7. How do I fix the B1439 code on a 2018 GMC Sierra?

Repairs may include tightening or cleaning electrical connections, replacing damaged wiring, updating the control module software, or replacing a faulty component.

8. Can a software update resolve the B1439 code?

In some cases, a software update to the vehicle's control module can resolve intermittent voltage issues if it's related to a firmware bug.

9. What tools are needed to troubleshoot the B1439 code?

You'll need a multimeter to check voltage and continuity, a scan tool to read and clear the code, and possibly wiring diagrams for the affected circuit.

10. How much does it cost to repair the B1439 code on a 2018 GMC Sierra?

Repair costs vary based on the issue but can range from $50 for a simple connection fix to several hundred dollars if a module or component needs replacement.