AutoCodes – GMC – P124A 2017 GMC Sierra

P124A 2017 GMC Sierra Code - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit

Quick Answer

The Engine Control Module (ECM) supplies voltage to each fuel injector on the injector high voltage supply circuits. Common causes include Faulty Fuel Injector 3, Fuel Injector 3 harness is open or shorted, Fuel Injector 3 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: P124A 2017 GMC Sierra indicates Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit.
Common causes: Common causes include Faulty Fuel Injector 3, Fuel Injector 3 harness is open or shorted, Fuel Injector 3 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 361

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 Aug 12, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P124A 2017 GMC Sierra Description

The Engine Control Module (ECM) supplies voltage to each fuel injector on the injector high voltage supply circuits. The ECM energizes each fuel injector by grounding the high voltage control circuit of the fuel injector. The ECM monitors the status of the injector high voltage supply circuits and the fuel injector high voltage control circuits. When a fuel injector circuit condition is detected by the ECM, the affected fuel injector(s) is disabled. The Diagnostic Trouble Code (DTC) will be set if the ECM detects the injector high control circuit is shorted to the low control circuit for greater than 2 s.

OBDII Code P124A 2017 GMC Sierra - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit - AutoCodes.com — P124A 2017 GMC Sierra Code - Injector 3 Positive Voltage Control Circuit Shorted to Control Circuit

What does this mean?

What are the Possible Causes of the DTC P124A 2017 GMC Sierra?

Faulty Fuel Injector 3
Fuel Injector 3 harness is open or shorted
Fuel Injector 3 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P124A 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 P124A 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 P124A 2017 GMC Sierra code?

Need more information on how to fix the P124A 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P124A 2017 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 2017 GMC Sierra Code

1. What does the OBDII code P124A mean on a 2017 GMC Sierra?

P124A indicates that the Injector 3 Positive Voltage Control Circuit is shorted to the control circuit, meaning there is an electrical issue affecting the injector's function.

2. What are the common symptoms of code P124A in a 2017 GMC Sierra?

Symptoms include rough idling, engine misfires, reduced fuel efficiency, decreased engine performance, or the engine failing to start.

3. What causes the P124A code to appear in a 2017 GMC Sierra?

Common causes include damaged wiring or connectors for injector 3, a faulty fuel injector, a short circuit, or an issue with the Powertrain Control Module (PCM).

4. Can a faulty injector cause the P124A code?

Yes, a malfunctioning fuel injector, particularly Injector 3, can cause this code due to electrical issues within the injector.

5. How do I diagnose the P124A code on a 2017 GMC Sierra?

Start by inspecting the wiring and connectors for Injector 3, check for signs of damage or corrosion, and use a multimeter to test for continuity or short circuits. If no issues are found, test the injector itself or the PCM.

6. Can I drive my 2017 GMC Sierra with a P124A code?

Itâ€™s not recommended to drive with this code, as it may lead to engine misfires, reduced performance, and potentially damage other components.

7. How much does it cost to fix the P124A code on a 2017 GMC Sierra?

Repair costs vary depending on the root cause. Replacing a damaged injector can cost $200â€“$500, while wiring repairs may be less. PCM replacement is more expensive, ranging from $500â€“$1200.

8. Does the P124A code mean the PCM is faulty?

Not necessarily. While a faulty PCM can cause the P124A code, itâ€™s less common. Electrical issues like damaged wiring or a bad injector are more likely.

9. How do I reset the P124A code after repairs?

After fixing the issue, clear the code using an OBDII scanner. Drive the vehicle to ensure the code does not return.

10. Can cleaning the injector fix the P124A code?

Cleaning alone may not resolve the issue if the problem is electrical. However, if the injector is clogged and causing related symptoms, cleaning could help improve performance.