AutoCodes – GMC – P0628 2018 GMC Sierra

P0628 2018 GMC Sierra Code - Fuel Pump Speed Output Circuit Low Voltage

Quick Answer

The Engine Control Module (ECM) supplies voltage to the fuel pump driver control module for 30 s when the ignition is on and continuously when the engine is running. Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver Control Module 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: P0628 2018 GMC Sierra indicates Fuel Pump Speed Output Circuit Low Voltage.
Common causes: Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver Control Module 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 381

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 15, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0628 2018 GMC Sierra Description

The Engine Control Module (ECM) supplies voltage to the fuel pump driver control module for 30 s when the ignition is on and continuously when the engine is running. While this voltage is being received, a serial data signal containing the desired fuel pump speed is also received from the ECM. After the voltage and data have been received the fuel pump driver control module actuates the brushless fuel pump by means of a high power three phase signal. The Diagnostic Trouble Code (DTC) will be set when the Fuel Pump Speed Output Circuit is short to ground for greater than 2 s.

OBDII Code P0628 2018 GMC Sierra - Fuel Pump Speed Output Circuit Low Voltage - AutoCodes.com — P0628 2018 GMC Sierra Code - Fuel Pump Speed Output Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0628 2018 GMC Sierra?

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

How to Fix the DTC P0628 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 P0628 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 P0628 2018 GMC Sierra code?

Need more information on how to fix the P0628 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the 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 P0628 2018 GMC Sierra Code

1. What does the OBDII code P0628 mean on a 2018 GMC Sierra?

P0628 indicates a problem with the fuel pump speed output circuit, specifically low voltage, which can affect the fuel pump's operation.

2. What are the common symptoms of P0628 on a 2018 GMC Sierra?

Symptoms include difficulty starting the engine, poor acceleration, engine misfires, reduced fuel efficiency, or the engine stalling.

3. What causes the P0628 code to appear on a 2018 GMC Sierra?

Common causes include a faulty fuel pump relay, damaged wiring or connectors in the fuel pump circuit, a failing fuel pump, or a malfunctioning fuel control module.

4. Can I drive my 2018 GMC Sierra with the P0628 code?

Driving with this code is not recommended, as it can lead to stalling or further damage to the fuel system.

5. How do you diagnose the P0628 code on a 2018 GMC Sierra?

Diagnosis involves inspecting the fuel pump circuit wiring and connectors, checking the fuel pump relay and control module, and testing the fuel pump for proper operation.

6. How can I fix the P0628 code on my 2018 GMC Sierra?

Repairs may include replacing damaged wiring, connectors, or the fuel pump relay, or replacing the fuel pump or fuel control module if necessary.

7. What tools are needed to diagnose and repair the P0628 code on a 2018 GMC Sierra?

Tools include a diagnostic scanner, a multimeter for testing voltage, and basic hand tools for inspecting and replacing components.

8. How much does it cost to repair the P0628 code on a 2018 GMC Sierra?

Repair costs vary depending on the issue but typically range from $100 to $500, depending on whether you need to replace the fuel pump or other components.

9. Can a bad battery cause the P0628 code on a 2018 GMC Sierra?

Yes, a weak or failing battery can cause voltage issues that may trigger this code.

10. Does the P0628 code on a 2018 GMC Sierra require professional repair?

While some issues like checking wiring and connectors can be done by DIYers, complex repairs like replacing the fuel control module may require professional assistance.