AutoCodes – Hyundai – P2123 Hyundai

P2123 Hyundai Code - Accelerator Position Circuit - High Input

Quick Answer

The Accelerator Pedal Position (APP) sensor is installed on the upper end of the accelerator pedal assembly. Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position 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: P2123 Hyundai indicates Accelerator Position Circuit - High Input.
Common causes: Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position 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 8,178

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 P2123 Hyundai Description

The Accelerator Pedal Position (APP) sensor is installed on the upper end of the accelerator pedal assembly. The sensor detects the accelerator position and sends a signal to the Engine Control Module (ECM).
Accelerator pedal position sensor has two sensors. These sensors are a kind of potentiometers which transform the accelerator pedal position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of the accelerator pedal and feed the voltage signals to the ECM. The ECM judges the current opening angle of the accelerator pedal from these signals and controls the throttle control motor based on these signals.
Idle position of the accelerator pedal is determined by the ECM receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine operation
such as fuel cut.

OBDII Code P2123 Hyundai - Accelerator Position Circuit - High Input - AutoCodes.com — P2123 Hyundai Code - Accelerator Position Circuit - High Input

What does this mean?

What are the Possible Causes of the DTC P2123 Hyundai?

Faulty Accelerator Pedal Position Sensor
Accelerator Pedal Position Sensor harness is open or shorted
Accelerator Pedal Position Sensor circuit poor electrical connection

How to Fix the DTC P2123 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 P2123 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 P2123 Hyundai Code

1. What does the OBDII code P2123 mean on a Hyundai?

P2123 indicates a high input signal in the accelerator position sensor circuit, meaning the sensor is sending voltage readings that are out of the expected range.

2. What are the symptoms of a P2123 code in a Hyundai?

Symptoms may include poor throttle response, reduced engine power, the car entering limp mode, or the Check Engine Light illuminating.

3. What causes the P2123 code in a Hyundai?

Common causes include a faulty accelerator pedal position sensor, damaged wiring or connectors in the sensor circuit, or a malfunctioning engine control module (ECM).

4. Can I drive my Hyundai with a P2123 code?

Driving with this code is not recommended as it can lead to unsafe driving conditions, such as sudden loss of acceleration or the vehicle entering limp mode.

5. How do I diagnose the P2123 code on a Hyundai?

Begin with a visual inspection of the accelerator pedal position sensor and its wiring. Use a scan tool to monitor live data from the sensor and check if the voltage readings are within the expected range.

6. How do I fix the P2123 code in a Hyundai?

Repairs may include replacing the accelerator pedal position sensor, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the ECM if necessary.

7. What tools are needed to troubleshoot a P2123 code?

A diagnostic scan tool, multimeter, and basic hand tools are typically needed to troubleshoot and repair this code.

8. Does a P2123 code always mean the accelerator pedal position sensor is bad?

No, the issue could also be with the wiring, connectors, or ECM. A thorough diagnosis is necessary to pinpoint the exact cause.

9. How much does it cost to fix a P2123 code on a Hyundai?

The cost can vary depending on the root cause. Replacing the accelerator pedal position sensor typically costs between $100 and $300, including parts and labor.

10. Can a P2123 code cause long-term damage to my Hyundai?

If left unaddressed, this code can lead to reduced drivability and potentially damage other components, such as the ECM, due to prolonged strain on the system.