2020 Audi S6 Has A Check Engine Light

Troubleshooting the Check Engine Light in Your 2020 Audi S6: Common Causes and Solutions

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Emissions System
0%
60% chance it's
Something else
The most common reasons a 2020 Audi S6 has a check engine light are an emissions system component, a sensor, or a catalytic converter.
  • Emissions System: A faulty emissions system component, such as an oxygen sensor or EGR valve, can lead to increased emissions and trigger the check engine light.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2020 Audi S6 has a check engine light?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

A faulty oxygen sensor is one of the most common causes of a check engine light. Symptoms may include a decrease in fuel mileage, hesitation or misfiring from the engine, rough idling or even stalling. A faulty sensor may cause the vehicle to fail an emissions test.

Any time there is an emissions fault the check engine light will be displayed. The purpose of the check engine light is to inform the driver that an emission related fault has been found, and that there are on-board diagnostic (OBD) trouble codes stored in the powertrain or engine control module. Additionally, since the emissions systems are so intertwined into engine control and transmission control systems, symptoms may include nearly any sort of drivability concerns. This may include harsh shifting, failure to shift, hesitation on acceleration, jerking, engine failure to start or run, loss of power, or any number of other drivability issues.

Due to the nature of electrical systems on modern vehicles, the range of problems these can cause are nearly limitless. However, there is a way to categorize them in two ways. Permanent and intermittent problems. Permanent problems appear and remain. This may be the vehicle will not start, the radio does not work, or the door chime will not turn off among many, many others. These problems are more straight-forward to diagnose since they present themselves at all time. This means there will always be a fault to find. Intermittent electrical problems, however, can be difficult or impossible to locate, since they appear then disappear without warning. The best case scenario for an intermittent issue is when replicating the problem is easily accomplished and understood. This allows a technician to make an issue semi-permanent, allowing them to find the fault. Other issues that come and go without warning and cannot be replicated on demand must occur when the technician is servicing the vehicle, otherwise there is no problem to correct. It is most important to understand that electrical system faults always require inspection, and can include the vehicle working in any manner, or not working at all.

Like we noted in the last section, general diagnosis symptoms are the most vague of the bunch. There are several diagnostic spectrums, electrical diagnosis, drivability diagnostics, engine diagnostics, transmission diagnostics, and the list could continue for about 5 or 10 more spectrums of diagnostics. The most important take-away here, is that general diagnostics are diagnostics that have no other spectrum in which they fit, or the problem is unknown. This means that any vehicle left outside of a repair facility with the keys and an authorization to perform diagnosis will be diagnosed under the general diagnosis spectrum.

When the Check Engine Light comes on, you may experience engine performance issues such as poor acceleration, rough idling, or an engine that won't start. In some cases, no abnormal symptoms will be experienced. Other systems like the transmission or ABS can cause the Check Engine Light to illuminate and lights for those systems can come on at the same time. Similar lights may say "Check Engine Soon", "Malfunction Indicator Light" or just "Check". In rare case the engine can overheat.

What are the initial diagnostic steps to take for a check engine light on a 2020 Audi S6?

When faced with a check engine light on your 2020 Audi S6, it's essential to adopt a systematic diagnostic approach. Start by visually inspecting the gas cap, as a loose or damaged cap is a common culprit that can easily trigger the warning light. Next, pay attention to any additional dashboard indicators or messages that may provide further insights into the problem. Utilizing an OBD-II scanner is a crucial step; by connecting it to the vehicle's diagnostic port, you can retrieve specific error codes that will guide you toward the underlying issue. Additionally, take note of any unusual symptoms your vehicle may be exhibiting, such as rough idling or poor acceleration, as these details can be invaluable in narrowing down the diagnosis. By following these initial steps, you can effectively gather the necessary information to address the check engine light and potentially resolve the issue on your own.

What are the common problems that could cause the check engine light to illuminate in a 2020 Audi S6?

When the check engine light comes on in a 2020 Audi S6, it can be a source of concern for any driver. Understanding the common problems that may cause this warning can empower you to take action. One frequent culprit is a loose gas cap, which can disrupt the fuel system's pressure and trigger the light. Another common issue is a faulty oxygen sensor, which plays a crucial role in regulating the air-fuel mixture; if it malfunctions, it can lead to poor engine performance and increased emissions. Additionally, problems with the catalytic converter, such as blockages or inefficiencies, can also illuminate the check engine light, indicating that the exhaust system is not functioning optimally. Other potential issues include a malfunctioning mass airflow sensor, which affects engine performance, and worn-out spark plugs that can cause misfires. An engine misfire itself, often stemming from ignition system problems or fuel delivery issues, can also trigger the light. Lastly, a faulty ignition coil can lead to significant performance issues, making it essential to address these problems promptly. For those looking to DIY, diagnosing these issues early can help prevent further damage and ensure your Audi S6 runs smoothly.

How urgent is it to address the check engine light on a 2020 Audi S6?

Addressing the check engine light on a 2020 Audi S6 is not just a matter of convenience; it is a critical step in ensuring the longevity and reliability of your vehicle. Ignoring this warning can lead to a cascade of issues, including reduced fuel efficiency and potential engine damage, which can be costly to repair. The sophisticated onboard diagnostics in modern vehicles like the Audi S6 can help identify the specific problem, but it is essential to act quickly. For DIY enthusiasts, while it may be tempting to delay seeking professional help, understanding the urgency of the situation is vital. A simple diagnostic scan can reveal whether the issue is minor, such as a loose gas cap, or something more serious that requires immediate attention. By prioritizing the check engine light, you not only safeguard your vehicle's performance but also enhance your safety on the road. Therefore, if you see that light illuminate, take it seriously and consider diagnosing the issue promptly to avoid further complications.

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