AutoCodes – Cadillac – P128D Cadillac

P128D Cadillac 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 Cadillac 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 1,181

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

What does this mean?

What are the Possible Causes of the DTC P128D Cadillac?

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 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 P128D 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 P128D Cadillac Code

1. What are the common symptoms of OBDII code P128D in a Cadillac related to the Fuel Rail Temperature Sensor 2 Signal Message Counter Incorrect?

The common symptoms include poor engine performance, reduced fuel efficiency, and illuminated Check Engine Light.

2. What are the possible causes of OBDII code P128D in a Cadillac?

Possible causes include a faulty fuel rail temperature sensor, issues with the wiring or connectors related to the sensor, or a problem with the Engine Control Module (ECM).

3. How can I diagnose the underlying issue causing OBDII code P128D in my Cadillac?

Diagnosis typically involves using a scan tool to read the code, checking the fuel rail temperature sensor's readings, inspecting the sensor's wiring and connectors for damage, and testing the ECM for proper functioning.

4. Can I continue driving my Cadillac with OBDII code P128D present?

It is not recommended to continue driving with this code present, as it can lead to further engine issues and potential damage. It is best to address the problem promptly.

5. How can I repair OBDII code P128D in my Cadillac?

Repair usually involves replacing the faulty fuel rail temperature sensor, repairing any damaged wiring or connectors, and clearing the code with a scan tool. In some cases, reprogramming the ECM may be necessary.

6. Is it possible to reset OBDII code P128D in a Cadillac without fixing the underlying issue?

While you can clear the code temporarily, it will likely return if the root cause is not addressed. It's essential to diagnose and repair the issue to prevent further problems.

7. How can I prevent OBDII code P128D from occurring in my Cadillac in the future?

Regular maintenance, such as checking the fuel system components and wiring for signs of wear, can help prevent this code from appearing. Addressing any issues promptly can also prevent future occurrences.

8. Are there any safety concerns associated with OBDII code P128D in a Cadillac?

While the code itself does not pose immediate safety risks, ignoring it can lead to potential engine issues that may compromise vehicle safety and performance. It's best to address the problem promptly.

9. Can a DIY enthusiast repair OBDII code P128D in a Cadillac, or is professional help recommended?

Depending on your skill level and access to tools, DIY repair is possible for this code. However, if you're unsure about diagnosing or repairing the issue, seeking professional help is recommended to ensure proper resolution.

10. How long does it typically take to repair OBDII code P128D in a Cadillac?

The repair time can vary based on the exact cause of the code and the complexity of the repair needed. In general, it can take anywhere from a few hours to a full day to diagnose and fix the issue.