P0629 2018 GMC Sierra Code - Fuel Pump Speed Output Circuit High Voltage
Quick Answer
The P0629 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates that there is a high voltage condition in the fuel pump speed output circuit. Common causes include Faulty fuel pump speed sensor, Short or open circuit in the wiring harness, Malfunctioning PCM. 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
- P0629 2018 GMC Sierra indicates Fuel Pump Speed Output Circuit High Voltage.
- Common causes
- Common causes include Faulty fuel pump speed sensor, Short or open circuit in the wiring harness, Malfunctioning PCM.
- 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 P0629 2018 GMC Sierra Description
The P0629 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates that there is a high voltage condition in the fuel pump speed output circuit. This code is typically triggered when the powertrain control module (PCM) detects that the voltage in the fuel pump speed output circuit is higher than the specified range. The fuel pump speed output circuit is responsible for controlling the speed of the fuel pump, which is crucial for maintaining the proper fuel pressure in the fuel system.
Common Causes of P0629 2018 GMC Sierra
- Faulty fuel pump speed sensor.
- Short or open circuit in the wiring harness.
- Malfunctioning PCM.
- Defective fuel pump.
- Corrosion or damage to electrical connections.
Symptoms of P0629 2018 GMC Sierra
- Check engine light illuminated on the dashboard.
- Reduced engine performance or hesitation during acceleration.
- Poor fuel efficiency.
- Engine stalling or difficulty starting.
How to Fix P0629 2018 GMC Sierra
- Begin by using a scan tool to verify the P0629 code and perform a comprehensive diagnosis of the fuel pump speed output circuit.
- Inspect the wiring harness for any signs of damage, corrosion, or loose connections. Repair or replace any damaged wiring as needed.
- Test the fuel pump speed sensor for proper operation and replace it if necessary.
- Check the fuel pump itself for any issues such as a malfunctioning motor or clogged filter. Replace the fuel pump if it is found to be defective.
- Clear the DTC and test drive the vehicle to ensure that the issue has been resolved and the code does not return.
Cost to Fix P0629 2018 GMC Sierra
The typical repair costs for addressing a P0629 code on a 2018 GMC Sierra can vary depending on the specific cause of the issue and the required repairs. In general, the cost of parts such as a fuel pump speed sensor or a new fuel pump can range from $100 to $500 or more. Labor costs for diagnosis and repair can add an additional $100 to $300 or more, depending on the shop's hourly rates and the complexity of the repair. Overall, the total cost for addressing a P0629 code can range from $200 to $800 or more. It's important to note that these are rough estimates, and actual costs may vary based on factors such as location, vehicle make and model, and the extent of the repairs needed. It's advisable to consult with a qualified mechanic or auto repair shop for a more accurate cost estimate based on your specific situation.
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