AutoCodes – GMC – P128D GMC

P128D GMC 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 GMC 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 1,143

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

What does this mean?

What are the Possible Causes of the DTC P128D GMC?

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 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 P128D 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 P128D GMC code?

Need more information on how to fix the P128D GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific GMC Models

P128D 2014 GMC Sierra — Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect
P128D 2015 GMC Sierra — Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect
P128D 2016 GMC Sierra — Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect
P128D 2017 GMC Sierra — Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect
P128D 2018 GMC Sierra — Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect

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 GMC Code

1. What are the common symptoms of OBDII code P128D GMC?

- Common symptoms include poor engine performance, reduced fuel efficiency, rough idling, and illuminated Check Engine light.

2. What does the OBDII code P128D GMC indicate?

- This code indicates that the Fuel Rail Temperature Sensor 2 Signal Message Counter is reporting incorrect data.

3. What are the possible causes of OBDII code P128D GMC?

- Potential causes include a faulty fuel rail temperature sensor, wiring issues, ECM (Engine Control Module) problems, or sensor calibration errors.

4. How can I diagnose the OBDII code P128D GMC?

- Diagnosis involves using a scan tool to read the code, checking the sensor's wiring and connections, and testing the sensor's resistance and output voltage.

5. Can I drive my vehicle with the OBDII code P128D GMC?

- It is generally not recommended to drive the vehicle with this code present, as it can lead to poor engine performance and potential fuel system issues.

6. How can I repair the OBDII code P128D GMC?

- Repair options may include replacing the faulty fuel rail temperature sensor, repairing any damaged wiring, recalibrating the sensor, or resetting the ECM.

7. Is it safe to ignore the OBDII code P128D GMC?

- Ignoring this code can lead to further issues with your vehicle's fuel system and engine performance, so it is best to address it promptly.

8. Can a DIY enthusiast fix the OBDII code P128D GMC?

- Depending on your skill level and access to tools, you may be able to replace the sensor or check the wiring yourself, but more complex diagnostics may require professional help.

9. How much does it cost to repair the OBDII code P128D GMC?

- The cost of repair can vary depending on the exact cause of the code, but it may involve a sensor replacement, which can range from $100 to $300 including parts and labor.

10. How long does it take to fix the OBDII code P128D GMC?

- The repair time can vary based on the extent of the issue and the availability of parts, but it usually takes a few hours to a day to diagnose and repair the code.