AutoCodes – Honda – P2128 Honda

P2128 Honda Code - Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage

Quick Answer

Accelerator Pedal Position (APP) sensor B is a part of the Electronic Throttle Control System (ETCS), and it is used to convert the position of the accelerator pedal into electrical signals. Common causes include Faulty Accelerator Pedal Position, Accelerator Pedal Position harness is open or shorted, Accelerator Pedal Position 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: P2128 Honda indicates Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage.
Common causes: Common causes include Faulty Accelerator Pedal Position, Accelerator Pedal Position harness is open or shorted, Accelerator Pedal Position 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 14,883

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P2128 Honda Description

Accelerator Pedal Position (APP) sensor B is a part of the Electronic Throttle Control System (ETCS), and it is used to convert the position of the accelerator pedal into electrical signals. Based on these signals, the Powertrain Control Module (PCM) controls the throttle actuator so that the throttle position agrees with the accelerator pedal position. If the signal voltage from APP sensor A is a set value or less, the PCM detects a malfunction and stores a Diagnostic Trouble Code (DTC).

OBDII Code P2128 Honda - Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage - AutoCodes.com — P2128 Honda Code - Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P2128 Honda?

Faulty Accelerator Pedal Position
Accelerator Pedal Position harness is open or shorted
Accelerator Pedal Position circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P2128 Honda?

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 does this mean?

Code Tech Notes

Powertrain Control Module (PCM) may have to be updated.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2128 Honda 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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Information for Specific Honda Models

P2128 2008 Honda Accord — Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage
P2128 2009 Honda Accord — Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage
P2128 2010 Honda Accord — Accelerator Pedal Position Sensor 'B' Throttle Position Sensor 'D' Circuit High Voltage

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.