AutoCodes.com | All About OBDII Engine Codes
AutoCodes - Scion - P2138 Scion

P2138 Scion Code - Throttle Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation

- Code Popularity: 8,067 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC P2138 Scion?

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 Accelerator Pedal Position (APP) Sensor
  • Accelerator Pedal Position Sensor harness is open or shorted
  • Accelerator Pedal Position Sensor circuit poor electrical connection
  • Faulty Engine Control Module (ECM)
⚠ Does your Scion have Safety Recalls? → Check here

How to Fix the DTC P2138 Scion?

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 P2138 Scion Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2138 Scion 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.

What are Code Possible Symptoms?

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

Code P2138 Scion Description

The Accelerator Pedal Position (APP) sensor is built into the accelerator pedal sensor assembly and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type sensor and uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the Engine Control Module (ECM), varies between 0.5 V and 4.75 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the accelerator pedal position sensor itself.
The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2 and controls the throttle actuator according to these signals.
When either the output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is more than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and stores a Diagnostic Trouble Code (DTC).

OBDII Code P2138 Scion - Throttle Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation - AutoCodes.com
P2138 Scion Code - Throttle Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation

Need More Information on the Code?

Need more information on how to fix the P2138 Scion code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2138 Scion code diagnosed by a professional: Find a repair shop in your area

Code P2138 Scion comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P2138 Scion code? Have you replaced any parts?
Any information is appreciated. Thanks