AutoCodes – Hyundai – P2128 Hyundai

P2128 Hyundai Code - Accelerator Position Circuit - High Input

Quick Answer

The Accelerator Pedal Position (APP) sensor is an input to the Powertrain Control Module (PCM) and used to determine the amount of torque requested by the operator. Common causes include Faulty Accelerator Pedal Position (APP) Sensor, Accelerator Pedal Position (APP) Sensor harness is open or shorted, Accelerator Pedal Position (APP) 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: P2128 Hyundai indicates Accelerator Position Circuit - High Input.
Common causes: Common causes include Faulty Accelerator Pedal Position (APP) Sensor, Accelerator Pedal Position (APP) Sensor harness is open or shorted, Accelerator Pedal Position (APP) 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 9,295

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
Cost to Diagnose
FAQs
Comments
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Code P2128 Hyundai Description

The Accelerator Pedal Position (APP) sensor is an input to the Powertrain Control Module (PCM) and used to determine the amount of torque requested by the operator. There are 2 pedal position signals in the sensor. Both signals, APP and APP2, have a positive slope (increasing angle, increasing voltage), but are offset and increase at different rates. The 2 pedal position signals make sure the PCM receives a correct input even if 1 signal has a concern. The PCM determines if a signal is incorrect by calculating where it should be, inferred from the other signals. If a concern is present with one of the circuits the other input is used. There are 2 reference voltage circuits, 2 signal return circuits, and 2 signal circuits (a total of 6 circuits and pins) between the PCM and the APP sensor assembly. The pedal position signal is converted to pedal travel degrees (rotary angle) by the PCM. The software converts these degrees to counts, which is the input to the torque based strategy.

OBDII Code P2128 Hyundai - Accelerator Position Circuit - High Input - AutoCodes.com — P2128 Hyundai Code - Accelerator Position Circuit - High Input

What does this mean?

What are the Possible Causes of the DTC P2128 Hyundai?

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

How to Fix the DTC P2128 Hyundai?

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 P2128 Hyundai 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 P2128 Hyundai Code

1. What does the OBDII code P2128 mean on a Hyundai?

P2128 indicates a problem with the Accelerator Pedal Position (APP) sensor circuit, specifically a high voltage input detected by the Powertrain Control Module (PCM).

2. What are the common symptoms of code P2128 in a Hyundai?

Symptoms include reduced engine performance, limp mode activation, delayed throttle response, or an illuminated Check Engine Light.

3. What causes code P2128 on a Hyundai?

Common causes include a faulty APP sensor, damaged wiring or connectors in the sensor circuit, or a malfunctioning PCM.

4. Can I drive my Hyundai with code P2128?

Itâ€™s not recommended to drive with P2128 for long distances, as it can lead to reduced throttle control and potentially unsafe driving conditions.

5. How do I fix code P2128 on a Hyundai?

Repairs may include replacing the APP sensor, repairing or replacing damaged wiring, cleaning the sensor connectors, or, in rare cases, replacing the PCM.

6. How is the P2128 code diagnosed on a Hyundai?

A technician will use a scan tool to confirm the code, inspect the APP sensor and its wiring, check for proper voltage and ground signals, and test the PCM if necessary.

7. How much does it cost to fix code P2128 on a Hyundai?

Repair costs can range from $100 to $400 depending on whether the APP sensor, wiring, or another component requires replacement.

8. Can a dirty throttle body cause code P2128 on a Hyundai?

A dirty throttle body is not a direct cause of P2128, but it can contribute to throttle-related issues that may trigger similar symptoms.

9. What tools are needed to troubleshoot code P2128?

Basic tools include a scan tool, multimeter for voltage testing, and possibly a wiring diagram for the APP sensor circuit.

10. How can I prevent code P2128 from occurring again on my Hyundai?

Regular maintenance, such as inspecting and cleaning the APP sensor and its connections, can help prevent future issues.

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