Engine-CodesLexus – P0120 Lexus

P0120 Lexus Code - Throttle / Pedal Position Sensor / Switch 'A' Circuit Malfunction

Quick Answer

The P0120 diagnostic trouble code (DTC) for Lexus indicates a malfunction in the throttle/pedal position sensor/switch 'A' circuit. Common causes include Wiring issues such as a short circuit or open circuit, A faulty throttle position sensor, Poor connections or corroded terminals. 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
P0120 Lexus indicates Throttle / Pedal Position Sensor / Switch 'A' Circuit Malfunction.
Common causes
Common causes include Wiring issues such as a short circuit or open circuit, A faulty throttle position sensor, Poor connections or corroded terminals.
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 10, 2024
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Code P0120 Lexus Description

The P0120 diagnostic trouble code (DTC) for Lexus indicates a malfunction in the throttle/pedal position sensor/switch 'A' circuit. This sensor is crucial for the proper functioning of the vehicle's electronic throttle control system. The sensor is responsible for monitoring the position of the accelerator pedal and sending this information to the engine control module (ECM) to determine the appropriate throttle response.

OBDII Code P0120 Lexus - Throttle / Pedal Position Sensor / Switch 'A' Circuit Malfunction
P0120 Lexus Code - Throttle / Pedal Position Sensor / Switch 'A' Circuit Malfunction

Common Causes of P0120 Lexus

  1. Wiring issues such as a short circuit or open circuit.
  2. A faulty throttle position sensor.
  3. Poor connections or corroded terminals.
  4. Issues with the engine control module (ECM).
  5. Environmental factors such as moisture or debris affecting the sensor's operation.

Symptoms of P0120 Lexus

  1. Erratic acceleration or lack of response when pressing the accelerator pedal.
  2. Rough idling or stalling when coming to a stop.
  3. Reduced fuel efficiency and increased emissions.
  4. Check Engine light illuminated on the dashboard.
  5. Limited power output or inability to accelerate smoothly.

How to Fix P0120 Lexus

  1. Begin by diagnosing the issue using a scan tool to read the specific trouble code and determine the exact cause of the malfunction.
  2. Inspect the wiring harness and connections related to the throttle position sensor for any signs of damage, corrosion, or loose connections.
  3. Test the throttle position sensor using a multimeter to check for proper voltage and resistance readings.
  4. If the sensor is determined to be faulty, replace it with a new, OEM-quality sensor to ensure proper functionality.
  5. Clear the DTC from the ECM's memory using the scan tool and test drive the vehicle to verify that the issue has been resolved.

Cost to Fix P0120 Lexus

The typical repair costs for addressing a P0120 code in a Lexus can vary depending on the specific model, year, and engine type. On average, replacing a throttle position sensor can cost between $100 and $300 for the part alone. Labor costs at a repair shop can range from $100 to $200 per hour, with the total repair time likely ranging from 1 to 2 hours. Therefore, the total cost for resolving this issue could be in the range of $200 to $600. It is advisable to consult with a trusted mechanic or dealership for a more accurate estimate based on your vehicle's specific needs.

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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 P0120 Lexus Code

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Discuss the causes and fixes for P0120 Lexus OBDII Code

  • I have a 1998 Lexus GS300 that i drove to work parked for lunch came out to go home would turn over but would not start. Used by scantool got two code P0120 and P1120 have you seen this issue before?