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P2123 OBD-II Trouble Code: Throttle/Pedal Position Sensor/Switch D Circuit High Input

Check Engine Light

P2123 Code Definition

Throttle/Pedal Position Sensor/Switch D Circuit High Input

What the P2123 code means

The P2123 trouble code indicates that the Engine Control Module (ECM), which is in charge of receiving a signal from the throttle position sensor, has detected a malfunction within one of the circuits of the throttle position sensor.

What are the causes of the P2123 code?

This code is usually only found on vehicles that have an electronic throttle body. With that taken into consideration, some of the possible causes of the P2123 trouble code may include:

  • 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 P2123 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 P2123 code?

  1. A mechanic may begin diagnosing the P2123 trouble code by popping the hood and locating the throttle body.

  2. Once the throttle body has been located, the mechanic would then check the wiring and connectors to the throttle body motor and throttle position sensor.

  3. If the wiring and connectors seem to be in good condition, the mechanic would then test the throttle position sensor and throttle body motor for proper function using the manufacturer’s recommended procedure.

  4. In the unlikely event that the problem is not found at this point, the mechanic would then test the Engine Control Module to ensure that it is operating properly.

Whichever parts are found to be faulty would be replaced at the customer’s request.

Common mistakes when diagnosing the P2123 code

A common mistake that could be made when diagnosing the P2123 trouble code would be to replace the throttle position sensor due to the fact that this part is mentioned in the trouble code definition. This is in fact the most common mistake when diagnosing any trouble code that mentions a part.

How serious is the P2123 code?

The P2123 trouble code should be considered very serious as it could cause drivability issues, such as preventing the vehicle from accelerating or even starting up. Even worse, this code can cause the vehicle to stall and leave the driver stranded. It is important to have the issue diagnosed and repaired as soon as possible in order to prevent being stranded on the side of the road.

What repairs can fix the P2123 code?

Additional comments regarding the P2123 code?

Oftentimes, mice and other small animals can get up under the hood of a vehicle from the underside and nest or sleep in small areas of the engine bay. These animals like to sleep in the engine bay because it is warm. While these animals are in the engine bay, they like to chew on wires they find. If this is the case, the driver may be able to easily locate the issue by looking around under the hood.

Need help with a P2123 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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