P0079 DTC Code: Causes, Symptoms, and Solutions


The P0079 DTC code is a diagnostic trouble code that is primarily associated with problems related to the exhaust gas temperature sensor circuit. This article will delve deep into the various aspects of the P0079 code, including its causes, symptoms, and possible solutions. By understanding this code in detail, you will be better equipped to diagnose and resolve any issues related to the exhaust gas temperature sensor.

Understanding the P0079 DTC Code:

The P0079 DTC code belongs to the range of powertrain codes, specifically related to the exhaust gas temperature sensor circuit “A.” It is a generic code that is used across various vehicle makes and models. The exhaust gas temperature sensor measures the temperature of the exhaust gases and provides this data to the engine control module (ECM) for optimal engine performance.

Causes of the P0079 DTC Code:

Several factors can trigger the P0079 DTC code. Understanding these causes is crucial for effective troubleshooting and repair. Here are some common reasons behind the occurrence of this code:

  1. Faulty Exhaust Gas Temperature Sensor: A malfunctioning or defective exhaust gas temperature sensor can trigger the P0079 code. This could be due to sensor failure, sensor wiring issues, or sensor circuit problems.

  2. Open or Shorted Circuits: Any open or shorted circuits within the exhaust gas temperature sensor circuit can lead to the activation of the P0079 code. These circuit issues can result from damaged wiring, loose connections, or corrosion.

  3. ECM Malfunction: In some cases, a faulty engine control module (ECM) can incorrectly interpret the data received from the exhaust gas temperature sensor, causing the P0079 code to appear.

  4. Exhaust System Problems: Issues within the vehicle’s exhaust system, such as exhaust leaks or clogged catalytic converters, can affect the accuracy of the exhaust gas temperature sensor readings and trigger the P0079 code.

Symptoms of the P0079 DTC Code:

When the P0079 code is triggered, it is important to be aware of the associated symptoms. Identifying these symptoms can help in accurate diagnosis and timely repairs. The common symptoms of the P0079 DTC code include:

  1. Check Engine Light: The illumination of the check engine light is one of the primary indications of the P0079 code. Modern vehicles are equipped with onboard diagnostic systems that detect and report any issues regarding engine performance.

  2. Engine Performance Issues: A malfunctioning exhaust gas temperature sensor can affect engine performance. You may experience reduced power, rough idling, or poor fuel efficiency.

  3. Increased Emissions: Since the exhaust gas temperature sensor plays a crucial role in regulating emissions, a faulty sensor can lead to increased emissions. This may result in the vehicle failing emission tests.

How to Diagnose and Fix the P0079 DTC Code:

To resolve the P0079 code, it is necessary to diagnose the underlying issue accurately. Here are the steps involved in diagnosing and fixing the P0079 DTC code:

  1. Use an OBD-II Scanner: Connect an OBD-II scanner to your vehicle’s diagnostic port to retrieve the specific code and additional related codes. This will provide valuable information regarding the issue.

  2. Inspect the Sensor and Wiring: Check the condition of the exhaust gas temperature sensor and its wiring. Look for signs of damage, corrosion, or loose connections. Replace or repair any faulty components.

  3. Scan the ECM: Perform a scan of the engine control module (ECM) to identify any underlying issues that may have triggered the P0079 code. If necessary, repair or replace the ECM.

  4. Check the Exhaust System: Inspect the exhaust system for any potential leaks, damages, or blockages. Repair any identified issues to ensure accurate readings from the exhaust gas temperature sensor.

  5. Clear the Code: After completing the necessary repairs, use the OBD-II scanner to clear the P0079 code from the ECM’s memory. This will turn off the check engine light.

Frequently Asked Questions (FAQs):

Q1: Can I continue driving with the P0079 DTC code?

A1: It is generally not recommended to continue driving with the P0079 code. While the vehicle may still be operable, a faulty exhaust gas temperature sensor can negatively impact engine performance and emissions. It is best to address the issue promptly to avoid further damage or potential failures.

Q2: How much does it cost to repair the P0079 DTC code?

A2: The cost of repairing the P0079 code can vary depending on the underlying cause and the specific vehicle make and model. It is advisable to consult a mechanic or an authorized service center for an accurate estimate based on your particular situation.

Q3: Can I fix the P0079 code by myself?

A3: If you have sufficient knowledge and experience in automotive repairs, you may be able to fix the P0079 code by yourself. However, proper diagnostic equipment and tools are required to accurately identify and resolve the issue. If you are unsure about your abilities, it is recommended to seek professional assistance.

In conclusion, the P0079 DTC code relates to exhaust gas temperature sensor circuit issues. Understanding the causes, symptoms, and solutions associated with this code is essential for successful diagnosis and repair. By following the recommended steps and consulting a professional if needed, you can effectively resolve the P0079 code and ensure optimal engine performance.

About author


Meet Sam Mitchell, your experienced and reliable guide in the complex world of car fault codes. With a robust career spanning over 15 years as a professional car mechanic, John has the skills, knowledge, and practical experience to help you navigate car fault issues with confidence.


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