AutoCodes – Toyota – P0123 2004 Toyota Prius

P0123 2004 Toyota Prius Code - Throttle Position Sensor/Switch 'A' Circuit High Input

Quick Answer

The Throttle Position Sensor (TPS) responds to the accelerator pedal movement. Common causes include Faulty throttle position sensor, Throttle position sensor harness is open or shorted, Throttle 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: P0123 2004 Toyota Prius indicates Throttle Position Sensor/Switch 'A' Circuit High Input.
Common causes: Common causes include Faulty throttle position sensor, Throttle position sensor harness is open or shorted, Throttle 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 3,954

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
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0123 2004 Toyota Prius 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 P0123 2004 Toyota Prius - Throttle Position Sensor/Switch 'A' Circuit High Input - AutoCodes.com — P0123 2004 Toyota Prius Code - Throttle Position Sensor/Switch 'A' Circuit High Input

What does this mean?

What are the Possible Causes of the DTC P0123 2004 Toyota Prius?

Faulty throttle position sensor
Throttle position sensor harness is open or shorted
Throttle position sensor circuit poor electrical connection

How to Fix the DTC P0123 2004 Toyota Prius?

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 does this mean?

Code Tech Notes

Before replacing any parts, try cleaning the throttle body and reset the light. If the codes come back, then it will necessary to replaced the throttle position sensor (TPS).

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0123 2004 Toyota Prius 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.

Need more information about the P0123 2004 Toyota Prius code?

Need more information on how to fix the P0123 2004 Toyota Prius code? Get Access to Factory Service Manuals

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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 2004 Toyota Prius Code

1. What are the common symptoms of OBDII code P0123 in a 2004 Toyota Prius?

- Common symptoms include issues with acceleration, rough idling, stalling, and possibly even a non-responsive throttle pedal.

2. What does the OBDII code P0123 mean for a 2004 Toyota Prius?

- OBDII code P0123 indicates that the throttle position sensor or switch 'A' circuit is detecting a high input signal.

3. What are the possible causes of OBDII code P0123 in a 2004 Toyota Prius?

- Possible causes include a faulty throttle position sensor, damaged wiring or connectors in the circuit, or issues with the engine control module.

4. How can I diagnose the cause of OBDII code P0123 in my 2004 Toyota Prius?

- You can use a multimeter to test the throttle position sensor, inspect the wiring for any damage, and check the connections for proper contact.

5. Can I still drive my 2004 Toyota Prius with OBDII code P0123?

- It is not recommended to drive the vehicle with this code as it can lead to performance issues and potentially unsafe driving conditions.

6. How do I repair OBDII code P0123 in my 2004 Toyota Prius?

- The most common repair is to replace the throttle position sensor, but it's also important to check and repair any damaged wiring or connectors in the circuit.

7. Is it possible to reset OBDII code P0123 in a 2004 Toyota Prius without fixing the issue?

- While you can clear the code with an OBDII scanner, it is not a permanent solution as the underlying issue causing the code will still remain.

8. Will OBDII code P0123 cause my 2004 Toyota Prius to fail emissions testing?

- Yes, OBDII code P0123 can cause your vehicle to fail emissions testing as it indicates a problem with the throttle position sensor circuit.

9. Can a DIY enthusiast fix OBDII code P0123 in a 2004 Toyota Prius?

- Yes, some DIY enthusiasts can fix this issue by following repair guides and using basic tools, but it's recommended to have some experience with automotive repairs.

10. How much does it typically cost to repair OBDII code P0123 in a 2004 Toyota Prius?

- The cost can vary depending on the exact cause of the issue, but replacing the throttle position sensor or fixing wiring/connectors can range from $100 to $300 at a repair shop.