AutoCodes – Chevrolet – P128A 2015 Chevrolet Silverado

P128A 2015 Chevrolet Silverado Code - Fuel Rail Pressure Sensor 1 Internal Performance

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 (FRP) Sensor, Fuel Rail Pressure 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: P128A 2015 Chevrolet Silverado indicates Fuel Rail Pressure Sensor 1 Internal Performance.
Common causes: Common causes include Low or no fuel, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure 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 445

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
Comments
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Code P128A 2015 Chevrolet Silverado 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 1 is greater than a predefined threshold for greater than 2.6 s.

OBDII Code P128A 2015 Chevrolet Silverado - Fuel Rail Pressure Sensor 1 Internal Performance - AutoCodes.com — P128A 2015 Chevrolet Silverado Code - Fuel Rail Pressure Sensor 1 Internal Performance

What does this mean?

What are the Possible Causes of the DTC P128A 2015 Chevrolet Silverado?

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

How to Fix the DTC P128A 2015 Chevrolet Silverado?

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 P128A 2015 Chevrolet Silverado 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 P128A 2015 Chevrolet Silverado 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.