AutoCodes – GMC – B144B 2018 GMC Sierra

B144B 2018 GMC Sierra Code - Run/Crank Power Relay Circuit

Quick Answer

The Body Control Module (BCM) controls the Ignition Main Relay (underhood) and the Ignition Main Relay (instrument panel left) through their control circuits by applying a voltage to the ignition run/crank relay coil control circuit. Common causes include Faulty Ignition Main Relay, Ignition Main Relay harness is open or shorted, Ignition Main Relay 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: B144B 2018 GMC Sierra indicates Run/Crank Power Relay Circuit.
Common causes: Common causes include Faulty Ignition Main Relay, Ignition Main Relay harness is open or shorted, Ignition Main Relay 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 219

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 Apr 20, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B144B 2018 GMC Sierra Description

The Body Control Module (BCM) controls the Ignition Main Relay (underhood) and the Ignition Main Relay (instrument panel left) through their control circuits by applying a voltage to the ignition run/crank relay coil control circuit. The Ignition Main Relay (underhood) and Ignition Main Relay (instrument panel left) are energized when the ignition switch is in the RUN or the CRANK position, or when a remote start is requested.
The Diagnostic Trouble Code (DTC) will be set when there is a fault in the Ignition Main Relay Circuit.

OBDII Code B144B 2018 GMC Sierra - Run/Crank Power Relay Circuit - AutoCodes.com — B144B 2018 GMC Sierra Code - Run/Crank Power Relay Circuit

What does this mean?

What are the Possible Causes of the DTC B144B 2018 GMC Sierra?

Faulty Ignition Main Relay
Ignition Main Relay harness is open or shorted
Ignition Main Relay circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B144B 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 B144B 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 B144B 2018 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 B144B 2018 GMC Sierra Code

1. What does the OBDII code B144B mean on a 2018 GMC Sierra?

The code B144B indicates an issue with the Run/Crank Power Relay Circuit, typically involving a malfunction in the relay or its associated wiring.

2. What are the common symptoms of the B144B code?

Symptoms may include the engine not starting, intermittent starting issues, or the vehicle stalling while driving.

3. What causes the B144B code in a 2018 GMC Sierra?

Common causes include a faulty run/crank relay, damaged wiring or connectors in the circuit, or a failure in the Body Control Module (BCM).

4. How do I diagnose the B144B code?

Start by checking the relay itself, inspecting the wiring and connectors for damage, and testing the circuit for proper voltage. If these are fine, the BCM should be examined.

5. Can a bad battery cause the B144B code?

Yes, a weak or faulty battery can cause voltage-related issues in the run/crank relay circuit, potentially triggering the B144B code.

6. How do I fix the B144B code on a GMC Sierra?

Repairs may include replacing the run/crank relay, repairing damaged wiring or connectors, or reprogramming or replacing the BCM if needed.

7. Is it safe to drive with a B144B code?

It is not recommended to drive with this code, as it can cause starting issues or unexpected stalling while driving, creating safety concerns.

8. How much does it cost to repair the B144B code?

Repair costs can vary but typically range from $50 to $200 for relay or wiring repairs, and up to $1,000 if the BCM needs replacement or reprogramming.

9. Can I clear the B144B code without fixing the issue?

Clearing the code without addressing the root cause is not recommended, as the issue will likely return and could lead to further problems.

10. Do I need a professional mechanic to fix the B144B code?

While some basic checks like inspecting the relay or wiring can be done by a DIYer, more complex issues like BCM diagnostics or programming require professional tools and expertise.