Engine-CodesChevrolet – P0123 Chevrolet

P0123 Chevrolet Code - Throttle Position Sensor Circuit High Voltage

Quick Answer

The P0123 code for Chevrolet indicates that there is a high voltage condition in the throttle position sensor (TPS) circuit. Common causes include Faulty TPS Sensor: The TPS sensor itself may be malfunctioning, sending incorrect voltage signals to the ECM, Damaged Wiring: Wiring harnesses or connectors in the TPS circuit may be damaged, leading to high voltage readings, ECM Malfunction: A malfunction in the engine control module can also cause high voltage in the TPS circuit. 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 Chevrolet indicates Throttle Position Sensor Circuit High Voltage.
Common causes
Common causes include Faulty TPS Sensor: The TPS sensor itself may be malfunctioning, sending incorrect voltage signals to the ECM, Damaged Wiring: Wiring harnesses or connectors in the TPS circuit may be damaged, leading to high voltage readings, ECM Malfunction: A malfunction in the engine control module can also cause high voltage in the TPS circuit.
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.
Table of contents Created and updated by William Orellana on Sep 08, 2024
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Code P0123 Chevrolet Description

The P0123 code for Chevrolet indicates that there is a high voltage condition in the throttle position sensor (TPS) circuit. The TPS is a crucial component of the vehicle's electronic control 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 determine the appropriate fuel delivery and ignition timing for optimal engine performance.

OBDII Code P0123 Chevrolet - Throttle Position Sensor Circuit High Voltage
P0123 Chevrolet Code - Throttle Position Sensor Circuit High Voltage

Common Causes of P0123 Chevrolet

  1. Faulty TPS Sensor: The TPS sensor itself may be malfunctioning, sending incorrect voltage signals to the ECM.
  2. Damaged Wiring: Wiring harnesses or connectors in the TPS circuit may be damaged, leading to high voltage readings.
  3. ECM Malfunction: A malfunction in the engine control module can also cause high voltage in the TPS circuit.
  4. Water Intrusion: Water or moisture entering the TPS sensor or circuit can cause electrical issues and trigger the P0123 code.
  5. Corrosion: Corrosion on the TPS sensor or connectors can disrupt the voltage signal and lead to high voltage readings.

Symptoms of P0123 Chevrolet

  1. Check Engine Light: The most common symptom associated with the P0123 code is the illumination of the Check Engine Light on the dashboard.
  2. Poor Acceleration: The vehicle may exhibit sluggish acceleration or respond poorly to throttle inputs.
  3. Rough Idling: The engine may idle roughly or inconsistently, with fluctuations in RPM.
  4. Reduced Fuel Efficiency: A high voltage in the TPS circuit can lead to inefficient fuel delivery, resulting in decreased fuel economy.
  5. Harsh Shifting: The transmission may experience harsh shifting or difficulty changing gears smoothly.

How to Fix P0123 Chevrolet

  1. Diagnostic Scan: Use a diagnostic scanner to retrieve the fault code and identify the specific issue triggering the P0123 code.
  2. TPS Sensor Replacement: Replace the throttle position sensor with a new, OEM-quality part to ensure accurate voltage readings.
  3. Check Wiring: Inspect the wiring harness and connectors in the TPS circuit for any damage or corrosion. Repair or replace as needed.
  4. Reset ECM: Clear the fault code and reset the engine control module to see if the issue persists after repairs.
  5. Test Drive: Take the vehicle for a test drive to ensure that the symptoms associated with the P0123 code have been resolved and that the engine is running smoothly.

Cost to Fix P0123 Chevrolet

The typical repair costs for addressing a P0123 code in a Chevrolet vehicle can range from $100 to $300, depending on the specific cause of the issue and the cost of parts and labor. This estimate does not include the cost of diagnostic scans or any additional repairs that may be needed. It is advisable to consult with a certified mechanic or auto repair shop to get an accurate quote for your vehicle, as rates can vary based on location and other factors.

Tech Notes for P0123 Chevrolet





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Information for Specific Chevrolet Models

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 Chevrolet Code

1. What are common symptoms of OBDII code P0123 in a Chevrolet related to the throttle position sensor circuit high voltage?

- Common symptoms include poor acceleration, reduced fuel efficiency, stalling or surging of the engine, and the vehicle going into limp mode.

2. What are the typical causes of the P0123 trouble code in a Chevrolet indicating high voltage in the throttle position sensor circuit?

- The main causes are a faulty throttle position sensor, a short or open circuit in the sensor's wiring, or a problem with the vehicle's ECM (engine control module).

3. How can I diagnose the P0123 code on my Chevrolet related to the throttle position sensor circuit high voltage?

- You can use a scan tool to read the trouble code and check the throttle position sensor's voltage output. Inspect the sensor's wiring for any damage or loose connections.

4. Can I still drive my Chevrolet with the P0123 code indicating high voltage in the throttle position sensor circuit?

- It's not recommended to drive the vehicle with this issue as it can lead to poor performance and potential safety hazards. It's best to address the problem promptly.

5. Are there any simple repair tips for fixing the P0123 code on a Chevrolet due to high voltage in the throttle position sensor circuit?

- Check the sensor's connector for corrosion, clean it if necessary, and ensure a secure connection. If the issue persists, consider replacing the throttle position sensor.

6. How much does it typically cost to repair the P0123 code on a Chevrolet caused by high voltage in the throttle position sensor circuit?

- The cost can vary depending on the specific model and labor rates, but replacing the throttle position sensor or repairing the wiring may range from $100 to $300.

7. Will resetting the trouble codes clear the P0123 code related to high voltage in the throttle position sensor circuit on my Chevrolet?

- Resetting the codes may temporarily clear the warning light, but if the underlying issue is not fixed, the code is likely to reappear after driving the vehicle.

8. Can a DIY enthusiast with basic automotive knowledge fix the P0123 code on a Chevrolet themselves?

- Yes, replacing the throttle position sensor or checking and repairing the wiring can be done by someone with basic automotive skills and the right tools.

9. What are the long-term effects of ignoring the P0123 code indicating high voltage in the throttle position sensor circuit of a Chevrolet?

- Ignoring the issue can lead to further damage to the engine, reduced fuel efficiency, and potentially unsafe driving conditions due to erratic throttle response.

10. Is it recommended to seek professional help to diagnose and repair the P0123 code on a Chevrolet related to high voltage in the throttle position sensor circuit?

- If you are unsure about diagnosing or fixing the issue yourself, it's best to consult a professional mechanic who can accurately diagnose the problem and perform the necessary repairs.

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