AutoCodes – GMC – P128D 2014 GMC Sierra

P128D 2014 GMC Sierra Code - Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect

Quick Answer

The fuel rail pressure sensor transmits fuel pressure and temperature information by serial data. Common causes include Faulty Fuel Rail Temperature Sensor 2, Fuel Rail Temperature Sensor 2 harness is open or shorted, Fuel Rail Temperature Sensor 2 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: P128D 2014 GMC Sierra indicates Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect.
Common causes: Common causes include Faulty Fuel Rail Temperature Sensor 2, Fuel Rail Temperature Sensor 2 harness is open or shorted, Fuel Rail Temperature Sensor 2 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 148

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 Sep 27, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P128D 2014 GMC Sierra Description

The fuel rail pressure sensor transmits fuel pressure and temperature information by serial data. The fuel rail pressure sensor internal microprocessor allows 4 separate sensor outputs from one 3 wire sensor. The Engine Control Module (ECM) supplies the fuel rail pressure sensor with a 5 V reference circuit, a low reference circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the fuel rail pressure sensor to the ECM. The ECM decodes the serial data signal into separate voltages which are displayed on a scan tool as the voltage inputs from the Fuel Temperature Sensor, Fuel Rail Pressure Sensor and Fuel Rail Pressure Sensor 2.

OBDII Code P128D 2014 GMC Sierra - Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect - AutoCodes.com — P128D 2014 GMC Sierra Code - Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P128D 2014 GMC Sierra?

Faulty Fuel Rail Temperature Sensor 2
Fuel Rail Temperature Sensor 2 harness is open or shorted
Fuel Rail Temperature Sensor 2 circuit poor electrical connection

How to Fix the DTC P128D 2014 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 P128D 2014 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 P128D 2014 GMC Sierra 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 P128D 2014 GMC Sierra Code

1. What does the OBDII code P128D mean on a 2014 GMC Sierra?

P128D indicates that the Fuel Rail Temperature Sensor 2 is sending an incorrect or inconsistent signal message counter to the engine control module (ECM).

2. What are the symptoms of a P128D code in a 2014 GMC Sierra?

Symptoms may include poor engine performance, reduced fuel efficiency, rough idling, possible engine stalling, or an illuminated check engine light.

3. What causes the P128D code to appear?

Common causes include a faulty fuel rail temperature sensor, wiring issues such as damaged or corroded connectors, or a malfunction in the ECM.

4. Can I drive my 2014 GMC Sierra with a P128D code?

Driving with a P128D code is not recommended as it may cause poor engine performance and could potentially lead to further damage if not addressed.

5. How do I diagnose a P128D code on a 2014 GMC Sierra?

Start by inspecting the wiring and connectors for the fuel rail temperature sensor for damage or corrosion. Use a scan tool to monitor sensor data and verify signal consistency.

6. How is the P128D code fixed in a 2014 GMC Sierra?

Repairs may include replacing the fuel rail temperature sensor, repairing damaged wiring or connectors, or reprogramming or replacing the ECM if necessary.

7. How much does it cost to repair a P128D code?

The cost can vary, but replacing a fuel rail temperature sensor typically ranges from $100 to $300, including parts and labor. Wiring repairs or ECM replacement may cost more.

8. What tools are needed to fix the P128D code?

You may need a multimeter to test wiring, a scan tool to read live data and clear the code, and basic hand tools for sensor replacement.

9. Can a dirty fuel system cause a P128D code?

A dirty fuel system is unlikely to directly cause a P128D code, but maintaining clean fuel injectors and filters is important for overall engine performance.

10. Will clearing the P128D code fix the issue?

Clearing the code may temporarily turn off the check engine light, but the underlying issue must be addressed to prevent the code from returning.