Understanding the P0123 Code in Dodge Vehicles: Causes, Fixes, and Prevention

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If you own a Dodge vehicle and the check engine light has turned on, you might be wondering what the problem is. The P0123 code is one of the diagnostic trouble codes that can indicate a problem with the throttle position sensor (TPS). In this article, we will explore what the P0123 code means, what causes it, and how to fix it.

What is the P0123 Code?

The P0123 code is a trouble code that is related to the throttle position sensor (TPS). The TPS is responsible for monitoring the position of the throttle in relation to the engine’s air intake. The information is then sent to the vehicle’s engine control module (ECM), which uses it to regulate the air/fuel mixture and the ignition timing. When the ECM detects an issue with the TPS, it will set the P0123 code, which triggers the check engine light to turn on.

What Causes the P0123 Code?

There are several potential causes of the P0123 code in Dodge vehicles:

Faulty TPS

A faulty TPS is the most common cause of the P0123 code. Over time, the sensor can wear out or become damaged, causing it to send incorrect signals to the ECM.

Wiring Issues

Wiring problems can also cause the P0123 code. Loose connections, damaged wires, or corroded terminals can all disrupt the signal between the TPS and the ECM.

ECM Issues

In rare cases, the P0123 code may be triggered by a problem with the ECM itself. This can occur if the ECM is not receiving the proper input from the TPS.

Symptoms of the P0123 Code

If your Dodge vehicle is experiencing the P0123 code, you may notice the following symptoms:

Check Engine Light

The most obvious symptom is the check engine light turning on. This is the ECM’s way of letting you know that there is a problem that needs to be addressed.
Reduced Power

If the TPS is not providing accurate information to the ECM, it may limit the amount of power that your vehicle can produce. This can make it difficult to accelerate or maintain speed.

Poor Fuel Economy

The inaccurate information from the TPS can also cause your vehicle to use more fuel than necessary, resulting in reduced fuel economy.

How to Fix the P0123 Code?

If you have received the P0123 code, there are several steps you can take to fix the problem:

Check the TPS

The first step is to check the TPS for any signs of wear or damage. You can use a multimeter to test the resistance of the sensor and ensure it is functioning properly.

Inspect the Wiring

If the TPS is not the issue, the next step is to inspect the wiring. Check for loose connections, damaged wires, or corroded terminals. Make any necessary repairs or replacements.

Replace the TPS

If the TPS is faulty, you will need to replace it. You can purchase a new sensor from your local auto parts store or online. Installation is typically straightforward and can be done with basic tools.

Reset the ECM

Once the repairs have been made, you will need to reset the ECM to clear the P0123 code. This can be done using an OBD-II scanner or by disconnecting the battery for a few minutes.

Preventing the P0123 Code

Preventing the P0123 code in your Dodge vehicle is essential for the long-term health and reliability of your vehicle. Here are a few tips to help you avoid the code:

Regular Maintenance

One of the best ways to prevent the P0123 code is by keeping up with your vehicle’s regular maintenance. This includes replacing worn parts, such as the TPS, before they fail.

Quality Parts

When replacing parts in your vehicle, it’s important to choose high-quality parts that are designed to last. This can help prevent issues like the P0123 code from occurring in the first place.

Safe Driving

Safe driving practices can also help prevent the P0123 code. Avoid harsh acceleration and braking, as this can put unnecessary stress on your vehicle’s components.


The P0123 code can be a frustrating issue for Dodge vehicle owners, but it’s important to address it as soon as possible to avoid further damage to your vehicle. By understanding the causes of the P0123 code and taking the necessary steps to fix it, you can keep your vehicle running smoothly and prevent future issues. Remember to always use high-quality parts and keep up with your vehicle’s regular maintenance to prevent the P0123 code from occurring in the first place.

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