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P2138 OBD-II Trouble Code: Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

Check Engine Light

P2138 Code Definition

Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation

What the P2138 code means

The P2138 trouble code indicates that the Engine Control Module has detected a malfunction within the D and/or E circuits of the throttle position sensor.

What are the causes of the P2138 code?

  • A defective throttle body motor

  • A damaged connector or wiring that is associated with the throttle body motor

  • A faulty throttle position sensor

  • A damaged connector or wiring that is associated with the throttle body motor

  • A faulty Engine Control Module

What are the symptoms of the P2138 code?

  • Vehicle may stall
  • Vehicle may not start
  • Vehicle may not accelerate well
  • A Check Engine Light will be illuminated

How does a mechanic diagnose the P2138 code?

  1. A mechanic may begin diagnosing the P2138 trouble code by locating the throttle body under the hood of the vehicle.

  2. Once located, the throttle body motor and throttle position sensor will be examined for circuitry issues related to the wiring and connectors.

  3. After that the mechanic would then test the throttle body motor and the throttle position sensor for proper function using the manufacturer’s recommended procedure.

  4. Finally, the mechanic would then test the Engine Control Module for proper function.

Any parts found to be faulty during this diagnosis would be replaced at the customer’s request.

Common mistakes when diagnosing the P2138 code

An easy mistake to make when diagnosing the P2138 trouble code would be to have the throttle position sensor replaced and ‘hoping’ it fixes the problem. Although this is one of the most common causes of the P2138 trouble code, it is not always the cause. Taking this into consideration, it is always important to fully test every aspect of a circuit to diagnose an electrical problem correctly.

How serious is the P2138 code?

I would consider the P2138 trouble code to be very serious. If I am late to work due to the fact that my car is not accelerating properly or stalling on the side of the road, I am not going to be very happy. With that said, I would recommend to anyone that has a P2138 trouble code stored to have the issue handled immediately.

What repairs can fix the P2138 code?

Additional comments regarding the P2138 code?

Do not ever try to manually open the butterfly valve in an electronic throttle body with your hand or any other tool. This can severely damage the electronic throttle body motor and possibly prevent the vehicle from being operational. It is always best to use safe and cautious practices when working with electrical equipment.

Need help with a P2138 code?

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