AutoCodes – GMC – P127D GMC

P127D GMC Code - Fuel Rail Pressure Sensor 2 Circuit High Voltage

Quick Answer

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to constantly adjust the high-pressure fuel pump's feed rate so that the ideal pressure is permanently maintained in the high-pressure section (between the high-pressure fuel pump and the injectors) by means of closed-loop control. Common causes include Low or no fuel, Faulty Fuel Rail Pressure Sensor 2, Fuel Rail Pressure Sensor 2 harness is open or shorted. 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: P127D GMC indicates Fuel Rail Pressure Sensor 2 Circuit High Voltage.
Common causes: Common causes include Low or no fuel, Faulty Fuel Rail Pressure Sensor 2, Fuel Rail Pressure Sensor 2 harness is open or shorted.
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 936

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 May 30, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P127D GMC Description

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to constantly adjust the high-pressure fuel pump's feed rate so that the ideal pressure is permanently maintained in the high-pressure section (between the high-pressure fuel pump and the injectors) by means of closed-loop control. The fuel rail pressure sensor transmits fuel pressure and temperature information via serial data to the ECM. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The ECM controls the fuel pressure regulator, which regulates high-pressure fuel that goes to the fuel injector rails and the injectors. The Diagnostic Trouble Code (DTC) will be set if the Fuel Rail Pressure Sensor 2 signal is greater than a predefined threshold for greater than 1s.

OBDII Code P127D GMC - Fuel Rail Pressure Sensor 2 Circuit High Voltage - AutoCodes.com — P127D GMC Code - Fuel Rail Pressure Sensor 2 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P127D GMC?

Low or no fuel
Faulty Fuel Rail Pressure Sensor 2
Fuel Rail Pressure Sensor 2 harness is open or shorted
Fuel Rail Pressure Sensor 2 circuit poor electrical connection
Faulty Fuel Pump

How to Fix the DTC P127D GMC?

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 P127D GMC 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 P127D GMC code?

Need more information on how to fix the P127D GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P127D GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P127D 2014 GMC Sierra — Fuel Rail Pressure Sensor 2 Circuit High Voltage
P127D 2015 GMC Sierra — Fuel Rail Pressure Sensor 2 Circuit High Voltage
P127D 2016 GMC Sierra — Fuel Rail Pressure Sensor 2 Circuit High Voltage
P127D 2017 GMC Sierra — Fuel Rail Pressure Sensor 2 Circuit High Voltage
P127D 2018 GMC Sierra — Fuel Rail Pressure Sensor 2 Circuit High Voltage

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 P127D GMC Code

1. What are the common symptoms of OBDII code P127D GMC (Fuel Rail Pressure Sensor 2 Circuit High Voltage)?

Symptoms may include rough idling, decreased fuel efficiency, power loss, and potential stalling of the vehicle.

2. What are the possible causes of OBDII code P127D GMC?

Possible causes include a faulty fuel rail pressure sensor, issues with the fuel system, wiring problems, or a problem with the Engine Control Module (ECM).

3. How can I diagnose the issue related to OBDII code P127D GMC?

Diagnosis may involve using a scan tool to read the code and data related to the fuel rail pressure sensor, checking the sensor's wiring for any damage, and conducting a fuel pressure test.

4. Can a DIY enthusiast repair OBDII code P127D GMC at home?

While some simple checks like inspecting wiring connections can be done at home, diagnosing and repairing the root cause of the code may require professional knowledge and tools.

5. Is it safe to drive with OBDII code P127D GMC active?

It is not recommended to drive with this code active, as it can lead to potential engine performance issues and further damage if left unaddressed.

6. How much does it typically cost to repair OBDII code P127D GMC?

The cost of repair can vary depending on the cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

7. Can OBDII code P127D GMC be triggered by a loose gas cap?

While a loose gas cap can trigger some codes related to the fuel system, OBDII code P127D GMC is specifically related to high voltage in the fuel rail pressure sensor circuit.

8. Are there any preventative maintenance tips to avoid OBDII code P127D GMC?

Regularly servicing the fuel system, checking for any signs of wear on wiring, and addressing any engine performance issues promptly can help prevent this code from appearing.

9. How long does it typically take to repair OBDII code P127D GMC?

The repair time can vary based on the exact cause of the issue and the availability of parts, but it may take a few hours to a full day for a mechanic to diagnose and fix the problem.

10. Can resetting the OBDII system clear the P127D GMC code?

Resetting the OBDII system may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear once the problem is detected again by the ECM.