AutoCodes – Cadillac – P128F Cadillac

P128F Cadillac Code - Fuel Rail Pressure Sensors 1 and 2 Signals 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 Pressure Sensor, Fuel Rail Pressure Sensor harness is open or shorted, Fuel Rail Pressure Sensor 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: P128F Cadillac indicates Fuel Rail Pressure Sensors 1 and 2 Signals Message Counter Incorrect.
Common causes: Common causes include Faulty Fuel Rail Pressure Sensor, Fuel Rail Pressure Sensor harness is open or shorted, Fuel Rail Pressure Sensor 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 1,409

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 P128F Cadillac 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 P128F Cadillac - Fuel Rail Pressure Sensors 1 and 2 Signals Message Counter Incorrect - AutoCodes.com — P128F Cadillac Code - Fuel Rail Pressure Sensors 1 and 2 Signals Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P128F Cadillac?

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

How to Fix the DTC P128F Cadillac?

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 P128F Cadillac 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.

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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 P128F Cadillac Code

1. What are the common symptoms of OBDII code P128F in a Cadillac related to Fuel Rail Pressure Sensors 1 and 2 Signals Message Counter Incorrect?

The common symptoms include rough engine idling, decreased fuel efficiency, loss of power during acceleration, and potential stalling of the vehicle.

2. What are the possible causes of OBDII code P128F in a Cadillac?

The possible causes include faulty fuel rail pressure sensors, issues with the fuel pressure system, wiring issues, or a problem with the Engine Control Module (ECM).

3. How can I diagnose the OBDII code P128F in a Cadillac?

Diagnosis typically involves using a scan tool to retrieve the specific trouble code, checking the fuel rail pressure sensor readings, inspecting the wiring for any damage, and testing the fuel pressure system for proper functioning.

4. Can I continue driving my Cadillac with the OBDII code P128F present?

It is not recommended to drive your Cadillac with this code present, as it can lead to further engine damage and potential safety hazards. It's best to address the issue promptly.

5. How can I repair OBDII code P128F in a Cadillac?

Repairing this code may involve replacing the faulty fuel rail pressure sensors, repairing any wiring issues, checking and correcting the fuel pressure system, and resetting the ECM after completing the repairs.

6. Are there any DIY tips for addressing the OBDII code P128F in a Cadillac?

While some basic troubleshooting steps can be done at home, it is advisable to seek professional help for diagnosing and repairing this code to ensure the correct fix and prevent further complications.

7. How much does it cost to repair OBDII code P128F in a Cadillac?

The cost of repairs can vary depending on the specific issue causing the code, the labor rates in your area, and whether you choose to go to a dealership or an independent mechanic. It's best to get a few quotes for an accurate estimate.

8. Can a faulty fuel rail pressure sensor cause other issues besides triggering the OBDII code P128F?

Yes, a faulty fuel rail pressure sensor can cause a range of issues, including poor engine performance, rough idling, hard starting, and even potential damage to other engine components if not addressed promptly.

9. How long does it typically take to repair OBDII code P128F in a Cadillac?

The repair time can vary depending on the exact cause of the code and the complexity of the fix. It could take anywhere from a couple of hours to a full day, depending on the extent of the repairs needed.

10. Is it necessary to reset the OBDII system after repairing the issue causing code P128F in a Cadillac?

Yes, it is important to reset the OBDII system after making the necessary repairs to clear the trouble code and ensure that the vehicle's ECM recognizes the fix.