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P0121 2003 Toyota Corolla Code - Throttle/Pedal Position Sensor/Switch 'A' Circuit Range/Performance 3ZZ-FE Engine

- Code Popularity: 4,492 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P0121 2003 Toyota Corolla?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty throttle position sensor
  • Throttle position sensor harness is open or shorted
  • Throttle position sensor circuit poor electrical connection
  • Faulty Engine Control Module (ECM)
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How to Fix the DTC P0121 2003 Toyota Corolla?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Search for P0121 2003 Toyota Corolla Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0121 2003 Toyota Corolla code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

When is the Code Detected?

Malfunction is detected when an excessively low or high voltage from the sensor is sent to ECM.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0121 2003 Toyota Corolla Description

The throttle position sensor (TPS) responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the Engine Control Module (ECM). In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.

OBDII Code P0121 2003 Toyota Corolla - Throttle/Pedal Position Sensor/Switch 'A' Circuit Range/Performance 3ZZ-FE Engine - AutoCodes.com
P0121 2003 Toyota Corolla Code - Throttle/Pedal Position Sensor/Switch 'A' Circuit Range/Performance 3ZZ-FE Engine

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