Blog Car Care Advice 5 Crucial Volvo Check Engine Light Causes: Should You Worry?
Car Care Advice

5 Crucial Volvo Check Engine Light Causes: Should You Worry?

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Your Volvo’s check engine light tells you there’s a problem that needs addressing.

However, when your check engine light illuminates, it won’t always provide the exact reason. It could be anything from a gas cap issue or an O2 sensor to a failing catalytic converter or spark plug.

We’ll discuss the causes of a check engine light and what to do if it illuminates on your Volvo’s dash.  

This Article Contains:

Let’s begin.  

What Causes the Volvo Check Engine Light to Turn On?

The onboard diagnostics system is a standard feature of most new Volvo vehicles. This also includes the Volvo inventory — Volvo XC90 and Volvo XC60. It triggers the check engine light on Volvo cars for several problems, like: 

1. Gas Cap Issues

A loose gas cap is one of the most common causes of an active check engine light. It prevents gas fumes from escaping and maintains pressure within the fuel tank. If you have a broken, missing, or loose gas cap, you’ll experience a drop in fuel pressure and reduced fuel economy – hence the illuminated check engine light on the driver display. 

2. Failing Catalytic Converter 

The catalytic converter’s function is to turn carbon monoxide in the exhaust system into carbon dioxide. When the catalytic converter clogs, carbon monoxide builds up and causes overheating in the engine. This leads to decreased performance and affects the fuel economy, which makes the check engine light illuminate.  

3. Fouled Spark Plugs or Spark Plug Wires 

Spark plugs start the engine by igniting the air-fuel mixture in the combustion chamber. They do this through electric charge transferred through the spark plug wires. Over time, unburned fuel causes carbon deposits to build up on each spark plug, reducing their effectiveness. 

The result?
Symptoms include poor performance, reduced power, and engine misfiring, which triggers the check engine indicator light on the driver display. 

4. Faulty Oxygen Sensor (O2 sensor)

The oxygen sensor (O2 sensor) detects oxygen levels in the exhaust gases and relays this information to the Electronic Control Unit (ECU). 

When oxygen sensors malfunction, the ECU receives inaccurate readings about the exhaust gases and supplies the engine with the wrong amount of fuel. This results in misfiring, poor engine performance, reduced fuel efficiency, and a lit Volvo engine check light. 

5. Faulty Mass Air Flow Sensor 

Mass airflow sensors detect how much air enters the engine. The sensors send information to the ECU to help maintain an optimal fuel-air ratio. 

However, it can wear out due to exposure to dirty air. This causes the ECU to produce the wrong fuel-air mixture, resulting in rough idling, difficulties starting the vehicle, misfiring, and a check engine indicator light. 

Now that you’re familiar with the causes of a Volvo engine check light, let’s learn more about what to do next. 

What to Do if Your Volvo Check Engine Light Turns On?

An illuminated check engine light means there’s a problem. However, you’re not always going to get a specific warning message. It could be an engine issue or something else like a throttle position sensor or aftermarket Volvo accessories. 

While you can use an OBD II scanner to read the fault code (especially if you have a new Volvo), how it illuminates also helps you learn more about what the issue is and how urgent a Volve service is. 

1. Check Engine Light Illuminates under Certain Circumstances

If the check engine light turns on sporadically, note any performance changes in your vehicle. A noticeable difference is a sign something is about to fail. It’s best to drive your vehicle as little as possible and get a check engine light diagnosis from a mechanic.

2. Check Engine Light Is Constantly On

If your check engine light is constantly illuminated, it means there’s a problem or you need a preventative schedule service. Take your Volvo car to a mechanic as soon as you can. 

A flashing check engine light indicates a severe problem, and it’s best not to drive at all. You can either have your vehicle towed or contact a mobile mechanic to come to you. 

4. Check Engine Light Is On and with Performance Issues

Consistently decreased engine performance accompanied by the check engine light indicates your vehicle may have entered “limp mode.” This feature of modern cars limits their driving capabilities to prevent further damage. You’ll need a mechanic to look at your Volvo car immediately as there’s a significant problem. 

5. Active Engine Light on Your EV, Hybrid, Mild Hybrid, or Plug-in Hybrid 

An illuminated check engine light on pure electric Volvo cars indicates several potential problems, including issues with your battery, battery cooling system, power inverter, traction motors, and charging port. 

For most hybrid models (mild hybrid and plug-in hybrid models), issues with the electric motor trigger a red triangle with an exclamation. But you will see the “regular” illuminated check engine light for gas engine issues.  

So you’ve had a mechanic fix the problem.
But what if the check engine light stays on?  

How to Perform a Check Engine Light Reset? 

A check engine warning light typically resets after the related problem is fixed. But if yours doesn’t go away and you’re certain there is no other issue, you can reset it manually.

If you have an OBD II scanner, plug it into your vehicle and clear the fault code. Your check engine light warning message should disappear after that. Most vehicles in the Volvo inventory are compatible with the scanner tool. 

You can also reset the warning light by holding the key in the first position while engaging the trip meter. Turn the ignition into the second position and wait for the service light to flash twice. Then, release the trip meter button. 

Before resetting the check engine light, ensure your vehicle is in good working condition, as it’s not always safe to drive with a check engine light on.

How Much Does It Cost to Get a Volvo Check Engine Light Diagnosed?

A check engine light diagnosis typically costs between $80-$120, depending on the number of service hours.

You’ll also need to cover the costs of the repair or replacement, which vary depending on the problem and the repair time involved. But here are some replacement cost estimates: 

Final Thoughts

There are lots of issues that trigger your check engine light. Some are severe (e.g., a broken throttle position sensor), and others, like a loose gas cap, are less concerning. But you should always proceed cautiously and get a mechanic to look at your vehicle.

Why not save yourself the trip and have a mobile mechanic like AutoNation Mobile Service come to you?

We service all Volvo cars (including the Volvo XC90 and Volvo XC60), make the process easy through online booking, and offer seven-day-per-week availability. We also provide a 12-month | 12,000-mile warranty on every repair. 

Contact us today for all your Volvo service needs.