Blog Car Care Advice Volkswagen Check Engine Light On: 7 Key Causes (+How to Fix)
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Volkswagen Check Engine Light On: 7 Key Causes (+How to Fix)

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We’ve all been there: You’re driving down the road when an ominous little orange light appears on your dashboard — it’s the Volkswagen check engine light.

What does the check engine light mean? 
Is your car about to break down? 
Can you keep driving, or should you pull over? 

It’s enough to worry even the most seasoned drivers. But don’t panic; we’re here to help.

Read on to discover some potential causes of Volkswagen check engine light, what to do when it happens, and more.

This Article Contains: 

Let’s dive in.

What Causes the Volkswagen Check Engine Light to Turn On?

Whether you’re driving the new Golf R, Volkswagen Jetta, VW Atlas, VW CPO, or any other Volkswagen vehicle, the dashboard lights are there to let you know how your car is performing. 

Although there are tons of reasons why your VW check engine light may activate, here are a few common ones:

1. Loose Gas Cap

If you notice a check engine light, there’s a very good chance it’s simply a loose gas cap. Your gas cap is responsible for keeping the fuel tank sealed, preventing fumes from escaping and any debris from landing in your fuel tank. The leaking vapors will reduce your fuel pressure and can result in a check engine light. Your fuel economy will also take a hit. 

2. Faulty Oxygen Sensor 

The oxygen sensor oversees the amount of oxygen in the exhaust gas. A faulty oxygen sensor can send inaccurate readings to the engine computer, causing the check engine light to activate.

3. Damaged Catalytic Converter

The catalytic converter reduces the emissions your car produces by converting the harmful pollutants into less toxic gases. However, over time, it can get clogged. A faulty catalytic converter can overheat and increase your vehicle’s emissions, triggering a check engine light.

4. Bad Spark Plug

It’s the job of each spark plug to ignite the air-fuel mixture inside the combustion chamber. A faulty spark plug may cause your engine to misfire, leading to the check engine warning light switching on.

5. Defective Thermostat

Your Volkswagen’s thermostat controls the flow of coolant to the engine, preventing the engine from overheating. However, a defective thermostat can prevent adequate coolant flow, causing the engine to reach dangerously high temperature levels. This will not only trigger the engine warning light but also impact engine performance. 

6. Damaged Mass Airflow Sensor

The mass airflow sensor (MAF) measures the air flowing into the intake manifold to ensure the right amount of air enters the engine for combustion. If the MAF is damaged, it may send incorrect readings to the engine computer, causing a misfire and activating the check engine light. Ignoring a faulty sensor will also affect your fuel economy. 

7. Faulty Ignition Coil 

The ignition coil transforms the battery’s low-voltage electrical current into a high-voltage current to ignite the fuel in the engine. A faulty ignition coil may send the incorrect voltage to the spark plug, leading to misfires and an active check engine light. 

8.  Damaged Throttle Body

The throttle body controls the amount of air allowed into the engine based on driver input, such as acceleration. When this is damaged or faulty, it can cause the engine to run rich or lean, throwing up a check engine light.

Next, let’s see what you should do if the check engine light activates.

What to Do If Your Volkswagen Check Engine Light Turns On?

In most cases, the VW check engine light should come on as a solid light on your dashboard. However, it can appear intermittently or flash as well. Let’s take a closer look at what that could mean.

A. Illuminates Under Certain Circumstances

This could indicate that the problem is intermittent. You may have a dirty or damaged sensor or a loose spark plug wire.

Diagnosing the issue can be challenging if the light doesn’t activate every time you drive your Volkswagen. The best bet here is to check if the gas cap is securely fastened, or if you have an OBD-II scanner, you could scan the code to get more information.

If you can’t diagnose the problem, it’s important to schedule service at your nearest service center as soon as possible.

B. Light Is Constantly On

If your VW check engine light is permanently on, it suggests a persistent issue with your engine or ignition system.

The cause could be anything, from a loose gas cap to a pending oil change. It’s best to play it safe and take your vehicle to a service center for a scheduled service, especially with the complexity involved in working on new vehicles. 

It’s also worth checking if any other dashboard lights activate to help narrow down the problem. For example, if the issue is tied to your EPC system (Electronic Power Control), the EPC system light should also activate.

Generally, a blinking check engine light indicates something more serious. If you’re driving and notice your check engine light is flashing, you should stop driving immediately. If the blinking check engine light is accompanied by vibration, reduced engine performance, or unusual noises, have your car towed to a service center as soon as you can.

Wondering how much it costs for a Volkswagen check engine light diagnosis?
Let’s find out. 

How Much Does a Volkswagen Check Engine Light Diagnosis Cost?

The average cost of a Volkswagen check engine light diagnosis for new vehicles is generally between $95 and $138, depending on the model.

However, more serious issues will likely incur more expensive repairs depending on the VW accessories that need replacement. For example, without vehicle protection plans, getting a new inventory for the catalytic converter or ignition coil will tend to push up repair prices.

Note: For cost-effective service tips, you should consult with a trained mechanic.  

Once the underlying cause is addressed, the light should go off. But if it doesn’t, you’ll need to rest it. 

How Do You Perform a Check Engine Light Reset? 

Since your check engine light is there to draw your attention to a possible issue, the best way to reset the light would be to diagnose and fix the problem. If you believe the problem is corrected, you can use an ODB-II scanner or VCDS (VAG-COM Diagnostic System) to reset it.

Although the check engine light is only supposed to deactivate with a smoothly running engine, disconnecting the battery can temporarily turn the dashboard lights off. However, if your engine has a problem, you should ideally schedule service first.

Final Thoughts

The check engine light can signify a wide range of issues, from something as minor as a loose gas cap to more serious engine problems. Either way, you should avoid driving with a check engine light on. As one of our service tips — book your car for a service before the light even comes up. 

Already past your VW Carefree Scheduled Maintenance?
Don’t worry  — AutoNation Mobile Service is at your service.

AutoNation Mobile Service is a mobile car repair and maintenance solution available seven days a week. Our expert mechanics will tackle the engine warning light in your Volkswagen Jetta, Gold R, VW Atlas, VW CPO, or another Volkswagen vehicle using original VW accessories. 

For an accurate cost estimate of a Volkswagen check engine light diagnosis and fix, fill out this form.