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Engine-Codes – Nissan – P0123 2002 Nissan Altima Sedan

P0123 2002 Nissan Altima Sedan Code - Throttle Position Sensor Circuit High Voltage

Quick Answer

The P0123 diagnostic trouble code (DTC) for a 2002 Nissan Altima Sedan refers to the Throttle Position Sensor (TPS) Circuit High Voltage. Common causes include Faulty TPS: A malfunctioning or worn-out TPS can send incorrect voltage signals to the ECM, triggering the P0123 code, Wiring Issues: Problems with the TPS wiring, such as a short or open circuit, can disrupt the signal and lead to a high voltage reading, ECM Malfunction: A faulty ECM can misinterpret the TPS signal, causing it to register as high voltage. 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
P0123 2002 Nissan Altima Sedan indicates Throttle Position Sensor Circuit High Voltage.
Common causes
Common causes include Faulty TPS: A malfunctioning or worn-out TPS can send incorrect voltage signals to the ECM, triggering the P0123 code, Wiring Issues: Problems with the TPS wiring, such as a short or open circuit, can disrupt the signal and lead to a high voltage reading, ECM Malfunction: A faulty ECM can misinterpret the TPS signal, causing it to register as high voltage.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 11, 2024
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Code P0123 2002 Nissan Altima Sedan Description

The P0123 diagnostic trouble code (DTC) for a 2002 Nissan Altima Sedan refers to the Throttle Position Sensor (TPS) Circuit High Voltage. The TPS is a crucial component of the vehicle's engine management system, as it monitors the position of the throttle valve and sends this information to the engine control module (ECM). The ECM uses this data to adjust the air-fuel mixture and ignition timing for optimal engine performance.

OBDII Code P0123 2002 Nissan Altima Sedan - Throttle Position Sensor Circuit High Voltage
P0123 2002 Nissan Altima Sedan Code - Throttle Position Sensor Circuit High Voltage

Common Causes of P0123 2002 Nissan Altima Sedan

  1. Faulty TPS: A malfunctioning or worn-out TPS can send incorrect voltage signals to the ECM, triggering the P0123 code.
  2. Wiring Issues: Problems with the TPS wiring, such as a short or open circuit, can disrupt the signal and lead to a high voltage reading.
  3. ECM Malfunction: A faulty ECM can misinterpret the TPS signal, causing it to register as high voltage.
  4. Throttle Body Problems: Mechanical issues within the throttle body, such as sticking or binding, can affect the TPS signal and trigger the P0123 code.

Symptoms of P0123 2002 Nissan Altima Sedan

  1. Check Engine Light: The most common symptom associated with the P0123 code is the illumination of the check engine light on the vehicle's dashboard.
  2. Reduced Performance: The vehicle may experience reduced performance, including decreased acceleration and overall power.
  3. Rough Idling: The engine may idle roughly or inconsistently, leading to vibrations and a shaky driving experience.
  4. Poor Fuel Efficiency: A high voltage signal from the TPS can result in improper fuel delivery, causing decreased fuel efficiency.
  5. Stalling: In severe cases, the engine may stall or shut off unexpectedly, especially during acceleration or at idle.

How to Fix P0123 2002 Nissan Altima Sedan

  1. Diagnose the Issue: Use a diagnostic scanner to retrieve the trouble codes, including P0123, and perform a thorough inspection of the TPS, wiring, and ECM.
  2. Test the TPS: Use a multimeter to test the TPS for proper voltage readings and functionality. Replace the TPS if it is found to be faulty.
  3. Check Wiring: Inspect the TPS wiring harness for any signs of damage, corrosion, or loose connections. Repair or replace any damaged wiring.
  4. Inspect Throttle Body: Check the throttle body for any mechanical issues, such as sticking or binding, that could affect the TPS signal. Clean or replace the throttle body as needed.
  5. Clear Codes: After completing the repairs, clear the trouble codes with a diagnostic scanner and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P0123 2002 Nissan Altima Sedan

The cost of repairing a P0123 code on a 2002 Nissan Altima Sedan can vary depending on the specific cause of the issue and the labor rates in your area. Typically, replacing a faulty TPS can cost between $100 and $200, while addressing wiring issues or replacing the throttle body can range from $200 to $500 or more. Labor costs at auto repair shops can range from $80 to $150 per hour, so the total repair cost may be between $300 and $800 or higher. It's recommended to obtain quotes from local auto repair shops to get a more accurate estimate based on your location and vehicle specifics.

When is the Code Detected?

An excessively high voltage from the Throttle Position (TP) Sensor is sent to Engine Control Module (ECM).

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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 P0123 2002 Nissan Altima Sedan Code

1. What are the common symptoms of OBDII code P0123 in a 2002 Nissan Altima Sedan?

The common symptoms of code P0123 in a 2002 Nissan Altima Sedan include issues with acceleration, rough idling, and potential stalling of the vehicle.

2. What causes the Throttle Position Sensor Circuit High Voltage code in a 2002 Nissan Altima Sedan?

The P0123 code in a 2002 Nissan Altima Sedan is often triggered by a faulty throttle position sensor, wiring issues, or a problem with the engine control module.

3. How can I diagnose the Throttle Position Sensor Circuit High Voltage issue in my 2002 Nissan Altima Sedan?

To diagnose the P0123 code, you can use an OBDII scanner to read the code, visually inspect the throttle position sensor and its wiring, and perform voltage tests on the sensor.

4. Can a dirty throttle body cause the P0123 code in a 2002 Nissan Altima Sedan?

Yes, a dirty throttle body can sometimes cause incorrect readings by the throttle position sensor, leading to the P0123 code being triggered.

5. How do I repair the Throttle Position Sensor Circuit High Voltage issue in my 2002 Nissan Altima Sedan?

Repairing the P0123 code may involve replacing the throttle position sensor, repairing any damaged wiring, cleaning the throttle body, or resetting the engine control module.

6. Is it safe to continue driving my 2002 Nissan Altima Sedan with the P0123 code present?

It is not recommended to continue driving your vehicle with the P0123 code as it can lead to poor engine performance and potential safety hazards.

7. Can I reset the P0123 code in my 2002 Nissan Altima Sedan by disconnecting the battery?

Disconnecting the battery may temporarily clear the code, but it is important to address the underlying issue causing the P0123 code to prevent it from recurring.

8. How much does it typically cost to repair the Throttle Position Sensor Circuit High Voltage issue in a 2002 Nissan Altima Sedan?

The cost of repairing the P0123 code can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

9. Will the P0123 code in my 2002 Nissan Altima Sedan cause the check engine light to illuminate?

Yes, the P0123 code will trigger the check engine light to illuminate in your 2002 Nissan Altima Sedan to alert you to a potential issue with the throttle position sensor circuit.

10. Can a DIY enthusiast fix the P0123 code in a 2002 Nissan Altima Sedan, or is it best left to a professional mechanic?

While some DIY enthusiasts may be able to address the P0123 code by replacing the throttle position sensor or cleaning the throttle body, it is recommended to consult a professional mechanic for accurate diagnosis and repair.

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