Engine-Codes.com
Engine-Codes – GMC – P124A 2018 GMC Sierra

P124A 2018 GMC Sierra Code - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit

Quick Answer

The diagnostic trouble code P124A for a 2018 GMC Sierra indicates that there is a short circuit between the injector 3 positive voltage control circuit and the control circuit. Common causes include Faulty fuel injector, Short circuit in the wiring harness, Faulty engine control module (ECM). 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
P124A 2018 GMC Sierra indicates Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit.
Common causes
Common causes include Faulty fuel injector, Short circuit in the wiring harness, Faulty engine control module (ECM).
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 10, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P124A 2018 GMC Sierra Description

The diagnostic trouble code P124A for a 2018 GMC Sierra indicates that there is a short circuit between the injector 3 positive voltage control circuit and the control circuit. In simpler terms, this means that there is an electrical issue with the fuel injector on cylinder 3. The fuel injector is responsible for delivering the precise amount of fuel into the combustion chamber at the right time. When there is a short circuit between the positive voltage and control circuit, it can disrupt the injector's operation and lead to potential performance issues with the vehicle.

OBDII Code P124A 2018 GMC Sierra - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit
P124A 2018 GMC Sierra Code - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit

Common Causes of P124A 2018 GMC Sierra

  1. Faulty fuel injector
  2. Short circuit in the wiring harness
  3. Faulty engine control module (ECM)
  4. Poor connection at the injector connector
  5. Electrical issues in the vehicle's electrical system

Symptoms of P124A 2018 GMC Sierra

  1. Rough idling or misfiring engine
  2. Decreased fuel efficiency
  3. Lack of power and acceleration
  4. Engine stalling or difficulty starting
  5. Check Engine Light illuminated on the dashboard

How to Fix P124A 2018 GMC Sierra

  1. Diagnose the specific cause of the short circuit using a diagnostic scanner and multimeter.
  2. Inspect the wiring harness for any visible damage or wear and repair or replace as needed.
  3. Test the fuel injector for proper operation and replace if faulty.
  4. Check the engine control module (ECM) for any signs of damage or malfunction and repair or replace as necessary.
  5. Clear the diagnostic trouble code from the vehicle's memory and test drive to ensure the issue has been resolved.

Cost to Fix P124A 2018 GMC Sierra

The typical repair costs for addressing a P124A code on a 2018 GMC Sierra can vary depending on the specific cause of the issue. In general, the cost of replacing a fuel injector can range from $150 to $300 per injector, with labor costs typically adding another $100 to $200 per hour. If the issue is related to a wiring harness or ECM problem, the repair costs can vary significantly. It is advisable to consult with a trusted mechanic or dealership for a more accurate estimate based on the specific diagnosis and repair needed. Keep in mind that labor rates at auto repair shops can vary, so it's essential to inquire about rates in your area for a precise cost estimate.

Need more information about the P124A 2018 GMC Sierra code?

Need more information on how to fix the P124A 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P124A 2018 GMC Sierra 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 P124A 2018 GMC Sierra Code

1. What does the OBDII code P124A mean on a 2018 GMC Sierra?

P124A indicates a problem with Injector 3’s positive voltage control circuit, specifically a short between the positive control circuit and the control circuit.

2. What are the common symptoms of code P124A in a 2018 GMC Sierra?

Symptoms may include rough idle, engine misfires, reduced power, poor fuel efficiency, and an illuminated check engine light.

3. What causes the P124A code to appear on a 2018 GMC Sierra?

The code can be caused by damaged or corroded wiring, a short circuit, a faulty fuel injector, a bad engine control module (ECM), or loose electrical connections.

4. Can a bad fuel injector cause the P124A code?

Yes, a faulty or failing fuel injector for cylinder 3 can cause this code by creating electrical issues in its control circuit.

5. How do I diagnose the P124A code on my 2018 GMC Sierra?

Start by inspecting the wiring and connectors for Injector 3 for damage or corrosion. Use a multimeter to check for continuity and shorts in the circuit, and test the injector itself for proper operation.

6. Is it safe to drive my 2018 GMC Sierra with the P124A code?

It’s not recommended to drive with this code, as it may lead to further engine damage or unsafe driving conditions due to misfires or reduced power.

7. How do I fix the P124A code on a 2018 GMC Sierra?

Repairs may include replacing damaged wiring or connectors, repairing short circuits, replacing Injector 3, or reprogramming or replacing the ECM if necessary.

8. How much does it cost to fix the P124A code on a 2018 GMC Sierra?

Repair costs vary but may range from $100 to $300 for wiring repairs or up to $500+ if the injector or ECM needs replacement.

9. Can a dirty connector cause the P124A code?

Yes, a corroded or dirty connector can create poor electrical contact, potentially causing the circuit to short and trigger this code.

10. Does clearing the P124A code with a scan tool fix the problem?

Clearing the code will reset the check engine light, but it won’t fix the underlying issue. The problem must be diagnosed and repaired to prevent the code from returning.

Discuss the causes and fixes for P124A 2018 GMC Sierra OBDII Code

Submit a New Comment

Code P124A 2018 GMC Sierra comments

No comments found for this page.