There could be several reasons why a Volkswagen check engine light stays on, but the most common issue with VWs is failed ignition coils. This guide covers some of the most common problems that trigger the check engine light on a Volkswagen. We also show you how to troubleshoot the VW check engine light yourself. It is important to diagnose and repair the issue as soon as possible, as the check engine light can lead to other problems if ignored.
The most common problem that triggers the check engine light on Volkswagen vehicles is bad ignition coils and, quite often, faulty spark plugs. Both these parts set engine misfire codes in the ECU, and if more than one coil or spark plug is faulty, it will trigger multiple cylinder misfires, and the check engine starts to flash on and off.
Symptoms
In addition to the check engine light, you may notice a few more symptoms, such as:
- Engine Running Rough
- Engine Misfire / Car Shaking
- Reduction or Lack of power
- Poor throttle response
- Unusual sounds from the engine
- Smoke from the exhaust
- Check Engine Light Flashing / Blinking
- Engine RPMs are high or unstable at idle
Don’t ignore these symptoms, especially if the check engine is flashing. Driving while the check engine light is flashing can lead to serious engine damage and overheating.
Common Problems
If the vehicle runs and drives fine, but the check engine light stays on, the most likely issue is an EVAP leak. To narrow down the problem, use the YOUCANIC scanner to read the codes via the OBD-II port.
- Faulty oxygen sensor
- Bad spark plugs
- Ignition coils
- Mass airflow (MAF) sensor
- EVAP leaks, such as loose gas cap
- Catalytic converter
- Vacuum leak
Hundreds of possible problems can trigger the check engine light on a Volkswagen. Read the fault codes to determine why your check engine light is on.
The Check Engine Light (CEL) on your Volkswagen (Jetta, Passat, Golf, Tiguan, etc.) can come on for many reasons, including defective mass airflow sensor, bad thermostat, engine temperature sensor, short in main wire harness, vacuum leak, worn spark plugs and failed ignition coils.
1. Gas Cap
A loose gas cap can trigger a Volkswagen engine light to turn on. Make sure you tighten the gas cap until you hear it click. If you read the codes, still get a code for EVAP system leak, inspect or replace the gas cap.
Sometimes the seal can crack and not seal the fuel tank properly. You can drive the vehicle, and the light will reset after a few driving cycles. Or use a YOUCANIC Scanner to reset the codes yourself.
2. Spark Plugs
Worn spark plugs are another common problem that triggers the VW check engine light. Typically you should change your VW spark plugs at the 90,000-mile mark. Volkswagen owners often forget to perform this maintenance and end up with CEL coming around the 120,000-mile mark.
3. Oxygen Sensor
Bad O2 sensors are another common reason the VW check engine light comes on. The oxygen sensors on Volkswagen vehicles often fail in the 80,000 to 100,000-mile range.
Volkswagens aren’t the only cars suffering from oxygen sensor issues. Audi, BMW, Mercedes-Benz, Porsche, Toyota, and Honda struggle to make oxygen sensors that last forever.
4. Ignition Coil
Volkswagens are famous for ignition coils frequently failing in their four-cylinder 1.8 and 2.0T engines. Sometimes, a brand-new ignition coil can malfunction or last less than 10,000 miles.
When VW ignition coils fail, the check engine light will flash on and off, the engine will shake, plus you will have a poor throttle response. When reading the codes with an OBD2 scanner, you will get P0300, P0301, and P0302.
5. Coolant Temperature Sensor
Volkswagen engine coolant temperature sensor can fail, triggering the check engine light to come on. Replacing the temperature sensor is a simple DIY fix many VW owners can perform at home.
If your Volkswagen check engine light is continuously ON, it can be due to many possible issues. You will need to read the codes with an OBD2 scanner. The problem can be as simple as a loose fuel tank cap or a bad spark plug, but it can also indicate a severe engine problem.
How to Reset Volkswagen Check Engine Light
Below you will find instructions on reading VW Diagnostic Trouble Codes (DTC). To clear the check engine light, you must first fix the problem and use the YOUCANIC scanner to clear the fault codes.
Procedure
- Locate an ODB port in your VW – it is usually under the dashboard on the driver’s side.
- Plugin your OBD2 scan tool and let it connect to the car. Turn the car ignition on to illuminate your dashboard (don’t turn the engine on).
- Scan for error codes. Store codes or write them down. Research the codes and what could be causing the problem in your VW.
- Reconnect the scanner and select Clear Codes to reset the VW engine light.
- Turn the ignition off and wait for several seconds. Turn the engine on and check to ensure the check engine light is off.
It’s important to have your Volkswagen checked by a professional mechanic to determine the cause of the check engine light. They can diagnose the problem and recommend the necessary repairs to fix it. To find out precisely what is wrong, use the YOUCANIC Full System scanner to read the codes via the diagnostic port under the dashboard (driver’s side).
What does it mean when the VW check engine light is flashing?
When your Volkswagen check engine light is flashing, the onboard diagnostic system has detected a misfire. This is due to fuel not getting burned in the cylinder. A bad spark plug or ignition coil typically causes this problem. It can also indicate a blown head gasket or clogged catalytic converter.
A flashing check engine light is a definitive sign of abnormal combustion. Never ignore your VW engine light or drive the car for an extended time, especially if your Volkswagen CEL is flashing.
Driving a Volkswagen with a flashing check engine light could devastate your engine and catalytic converter. If the engine overheats, pull over and turn off the car. Never drive your VW hard or even moderately if your Check Engine light flashes.
Should I Drive with Check Engine Light On?
It’s generally not a good idea to drive a vehicle with the check engine light on, especially if you have noticed any other issues or warning signs with your vehicle. The check engine light is a warning that something is wrong with your vehicle, and it’s important to check it as soon as possible.
If you have to drive your Volkswagen with the check engine light on, it’s important to pay attention to any other warning signs or issues you may be experiencing. Suppose you notice any changes in how your vehicle is running or experience any other driving problems. In that case, it’s important to stop driving and have your Volkswagen checked by a professional mechanic as soon as possible.
It’s also a good idea to avoid driving at high speeds or for long distances if the check engine light is on, as this can put additional strain on your engine and potentially cause further damage.
It’s important to have your vehicle checked by a professional mechanic as soon as possible if the check engine light is flashing. This can save you time and money in the long run by preventing further damage to your vehicle.
In summary, it’s generally not recommended to drive a vehicle with the check engine light on, as this can cause further damage to your vehicle. If you must drive your Volkswagen with the check engine light on, pay attention to any other warning signs and have your vehicle checked by a professional mechanic as soon as possible or diagnose it yourself using the YOUCANIC full system scanner.
Frequently Asked Questions
Why is a check engine light in my VW on?
The car uses a Check engine light to warn you that something is not working properly. Problems are usually related to fuel injection and ignition or emission control systems.
How to reset the check engine light, Volkswagen Jetta?
To reset the check engine light on a Volkswagen Jetta, you will need to use an OBD-II scanner to clear the diagnostic trouble codes (DTCs) that have caused the check engine light to come on. Here’s how to do it:
1. Locate the diagnostic port: The diagnostic port is typically located under the dashboard on the driver’s side of the vehicle.
2. Connect the OBD-II scanner: Plug the OBD-II scanner into the diagnostic port and turn it on.
3. Retrieve the DTCs: Use the OBD-II scanner to retrieve the diagnostic trouble codes (DTCs) that have caused the check engine light to come on.
4. Clear the DTCs: Once you have retrieved the DTCs, use the OBD-II scanner to clear them from the vehicle’s computer.
5. Disconnect the OBD-II scanner: Once the DTCs have been cleared, turn off the OBD-II scanner and disconnect it from the diagnostic port.
6. Start the engine: Start the engine and verify that the check engine light is no longer illuminated.
It’s important to note that clearing the check engine light without addressing the underlying issue that caused it to come on can be dangerous and could potentially cause further damage to your vehicle. If you cannot determine the cause of the check engine light, it’s recommended that you have your Volkswagen Jetta checked by a professional mechanic.
How can I access error codes on my VW’s board computer?
The only way to read the stored codes is by using a scan tool. You can visit your dealer or an independent workshop or buy your own scan tool.
How can I know what the error codes mean?
Depending on your scan tool, you usually get a code without any written explanation. Especially if you have a cheap scan tool, just search that code and your car on the internet or forums.
What does the VW check engine code p0411 mean?
Error code P0411 indicates Incorrect Flow in the Secondary Air Injection System (SAI). This emission control system uses an air pump to flow fresh air into the exhaust system. Usual failure points are pumps, hoses, or check valves. A damaged exhaust system can cause this error, as well.
VW check engine light is, but the scanner shows no codes.
If you have a Check Engine light, but there are no stored codes, this usually means that your scan tool can only read generic powertrain codes. This is usually the case with cheaper OBD2 readers. VW has additional specific codes that more specialized scan tools can access.
What could cause VW to check the engine light after an oil change?
If you have a Check Engine light, but there are no stored codes, this usually means that your scan tool can only read generic powertrain codes. This is usually the case with cheaper OBD2 readers. VW has additional specific codes that more specialized scan tools can access.
What could cause VW to check the engine light after an oil change?
An oil change can not cause a Check Engine light. If it came on immediately after the oil change was done, probably some sensor or connector was unintentionally unplugged during this process.
What does a flashing Check Engine light on a VW mean?
A flashing check engine light typically indicates a severe issue with your vehicle that needs to be addressed immediately. It’s important to stop driving your vehicle as soon as possible and have it checked by a professional mechanic. A flashing check engine light is different from a steady check engine light. A steady check engine light typically indicates a less severe issue that needs to be addressed. Still, a flashing check engine light indicates a more serious problem that could cause further damage to your vehicle if not addressed immediately. Some common reasons for a flashing check engine light include the following: 1. A misfire: A misfire can cause the check engine light to flash and potentially damage the catalytic converter. 2. An issue with the fuel system: A problem with the fuel system, such as a faulty fuel pump or fuel injector, can cause the check engine light to flash. 3. An issue with the exhaust system: A problem with the exhaust system, such as a faulty catalytic converter or exhaust manifold, can cause the check engine light to flash. An issue with the ignition system: A problem with the ignition system, such as a faulty spark plug or ignition coil, can cause the check engine light to flash.
We hope you find the “Volkswagen Check Engine Light ON” guide helpful. Check these troubleshooting and repair guides for more help on your Volkswagen.