The service engine soon light often causes confusion among motorists. Its meaning can differ among vehicle models, but more often than not when it comes on, it’s not something you should overlook.
If the service engine soon light is on, this means that your vehicle is due a routine service such as an oil change or a filter change. It can sometimes mean that there is something minor wrong with the engine that you should get checked out the next time you are near home.
The service engine light is not the same as the check engine light. If the check engine light is flashing, then this usually means that there is something more serious wrong with your vehicle.
Why Does the service engine soon Light turn on (5 Common Reasons)
On some older vehicles, the check engine light and service engine soon light can be combined into one. The meaning and severity of the problem depends on, the color of the light and whether the light is flashing or not.
However, on most modern vehicles there will be a separate check engine light and service engine soon light.
If the service engine soon light comes on when you are driving, it’s usually nothing to worry about. You should check your vehicle manual for the exact meaning, but in most cases it means that your vehicle is due a routine service or fluid top up. Here are some common reasons why the service engine light comes on.
Reason 1. Your Car Is Due A Routine Service
All modern cars will notify you when a service is due. This is usually indicated via the service engine soon light. This can include regular service items such as engine oil replacement, new spark plugs, fuel filter replacement and air filter replacement and cabin (pollen) filter renewal.
The latest vehicles will often specify exactly which service is due, so the service engine soon light will come on and you may see a message on the car entertainment system screen describing what needs changing.
Reason 2. Engine fluids Are Low And Need Topping Up
If one or more of your engine fluids are low, this can cause a service engine soon light. Your engine has a few different types of fluids that may need topping up from time to time. These include engine oil, coolant or windshield washer fluid.
If the engine oil level goes below the recommended minimum then you will usually see another light on the dashboard that looks like a red oil can. This may appear with or without the service engine light. It’s important to top up the oil as soon as possible to avoid permanent engine damage.
Reason 3. The Diesel Particulate Filter Needs Replacing
If your vehicle is less than 10 years old and has a diesel engine fitted, then it more than likely has a diesel particulate filter fitted. These filters have a limited lifespan and usually need replacement or deep cleaning after 125,000 miles of driving.
A service engine soon light can indicate that the DPF is clogged and needs attention. If the diesel particulate filter is blocked you will also notice a reduction in engine power and the engine may be difficult to start when cold. Some vehicles will limit the power output of the engine to prevent damage, and this may trigger the check engine light too.
Reason 4. The Ad Blue Fluid Needs Topping Up
Newer diesel vehicles also utilise ad blue to lower emissions. The ad blue tank needs topping up every few 1000 miles, and the service engine light may come on when the ad blue levels get low.
Reason 5. Your Brake pads need to be replaced
Another common service item that needs regular attention are brake pads. Most vehicles these days will have a brake pad wear sensor fitted that will set off the engine service light when the brake pads wear out.
Some vehicles also have a separate brake service icon that will light up in red when the brakes need attention.
What are the different types of service engine soon light?
If your vehicle is fitted with a service engine soon light, it’s more than likely one of two types.
Type 1. The standard service engine soon light literally says ‘service engine soon’ and lights up red on the dashboard when a service is due.
This is commonly fitted to vehicles that require servicing at fixed intervals as deemed by the manufacturer.
For example, the engine oil, air filter and cabin filter may need to be changed together once a year, the light may also come on for spark plug replacement every three years. The light will only come on as a service reminder and is not tied to the current condition of the engine or the recent driving conditions.
Type 2. A more sophisticated service engine soon light based on condition based servicing.
This service routine splits all of the major service items up into separate events, each with its own service interval. For example, service engine soon on BMWs is set up in this way.
There are a collection of engine service icons that illuminate orange or red depending on how urgent the service is. On engine startup, the icon for the next service that is due, will flash up on the display. If it is not due immediately it will flash on in orange for a few seconds, and it will display red if it is due now or is over due.
What’s the difference between the check engine light and service engine soon light?
Assuming your vehicle has separate check engine and service engine soon lights, they will each illuminate under different circumstances.
A flashing check engine light indicates a problem with your engine. It is usually triggered when an engine sensor receives a signal that is outside the expected range. It can be caused by a faulty engine component such as a faulty fuel pump or fuel injector, or it can be caused by a faulty sensor. You should always investigate a check engine light as soon as possible so as not to cause engine damage.
A service engine soon light is telling you that your car is due a routine service. It will usually light up at set intervals, for example every 12 months or after a certain amount of mileage has been covered. You can ignore a service engine soon light for a few days or weeks, but you should get your car serviced on time so as not to cause problems in the long term.
What Next: What Should you do when service engine soon light comes on?
In most cases, the service engine soon light is not an urgent warning that there is something wrong with your car. If you are driving when it comes on, don’t panic.
If you are unfamiliar with your vehicle, then the first thing you should do is check the vehicle handbook so as to learn what type of service indicator is fitted to your car.
If there is a separate check engine light fitted, then the service engine soon light can usually be ignored until you get home.
If the engine is due a routine service, then you should get this done as soon as possible, and definitely within the next few hundred miles of driving. If a service is not due then you should investigate further what is going on.
Here are a few steps to take when the service engine soon light comes on.
1. Check the vehicle handbook
If the service engine soon light comes on, the first thing you should do is take a look at the vehicle handbook to see what is going on. Dashboard warning lights can differ slightly from vehicle to vehicle, so it’s a good idea to reference the handbook if you are going to solve the problem by yourself.
2. Check the Service log book
If you’ve just bought the vehicle recently and it’s not brand new, then it may in fact be due a routine service. Take a look at the service book (usually stored with the vehicle manual in the glove box) and check to see when the last engine service was carried out and compare this to the manufacturer recommended service interval.
3. Check Engine fluids and fluid caps
If the engine is not due a scheduled service, then the next thing you should do is take a quick look under the hood to see if anything obvious is wrong.
Start by dipping the engine oil (if your engine has a dipstick). Most cars will have a separate oil level warning light, but it doesn’t do any harm to make sure there is an adequate amount of oil in the engine.
You should also check the other fluid levels. Check the coolant level by looking at the amount of fluid in the coolant top-up bottle. It’s important to do this when the engine has cooled, as the coolant level will rise when the engine is hot. Also, don’t remove the coolant bottle cap if the engine is hot!
Locate the brake fluid reservoir and ensure that the brake fluid level is ok. Check the location of the reservoir in the handbook, but it can usually be located up under the windshield beside the master cylinder.
It’s also worth topping up the windshield washer fluid. Most cars have a separate warning light for the windshield fluid level, but it won’t do any harm to top it up so as to rule it out.
It’s also worth checking the transmission fluid level if possible. Many vehicles still have a transmission fluid dipstick for checking the levels. Low transmission fluid can cause all sorts of problems, and can trigger a dashboard warning light if it drops below the minimum level.
If any of the other fluids need topping up, then add the required fluid and tighten down all of the caps securely. Take your vehicle for a short drive, and if the service engine soon light goes out, then you’ve solved the problem. Otherwise move onto an engine diagnostic.
4. Run an engine diagnostic
If your vehicle does not have a separate check engine and service engine soon light, then the light may come on if there is a bigger problem with your vehicles’ engine.
A diagnostic code reader will give you access to the engine control unit and any error codes that may be stored in memory.
There are hundreds of different possible error codes, each relating to a particular engine system or engine component. Take a note of any error codes that are retrieved, and then clear them from memory.
Now take your vehicle for a drive and if the service engine soon light comes back on, run another diagnostic to see if the same error codes appear. If the light doesn’t come back on, or doesn’t come back on at all it may point to a false positive, or an intermittent fault.
How to Turn Off The service engine soon Light?
The best way to reset the service engine soon light is by using an OBD 2 diagnostic code reader. A good code reader will allow you to reset a service schedule item such as an oil change interval or engine filter service interval. Doing this will usually turn off the service engine light.
Sometimes topping up a fluid, or tightening a fluid cap such as the gas cap followed by a short drive, can turn off a service engine soon light. Once the engine has recognised that the problem is now solved; then it may turn off the light itself.
A diagnostic code reader can be used to turn off a service engine now light
If your vehicle has a shared check engine/service engine light then turning it off can get a bit more complicated. You should be able to turn the light off by clearing any error codes that are stored in the ECU memory. However, if the problem still persists the light will come back on during the next drive cycle. In this case, the only way to turn the light off permanently is to rectify the problem that is triggering the light.
If you don’t have a diagnostic code reader then there are vehicle specific steps that you can carry out to turn off dashboard warning lights. These differ from one vehicle brand to another, and usually involve pressing the gas pedal or buttons on the dashboard for set periods of time in a particular sequence.
It would be impossible to cover all of the different sequences for all vehicles, but here’s a few that may work for popular vehicles.
1. How to reset service engine soon light Nissan
- Turn the ignition key to the on position but don’t start the engine
- Wait for 3 to 5 seconds.
- Press and release the gas pedal 5 times in quick succession
- Wait for 7 seconds and then press and hold the gas pedal for 10 seconds exactly
- The service engine light should now start flashing. Release the gas pedal now
- Press and hold down the gas pedal for another 10 seconds.
- The service engine light should stop flashing.
- Turn the key in the ignition to the off position.
- The service engine soon light will now be turned off when you restart the engine.
2. How to reset service engine soon light bMW
- Put the key in the ignition but don’t start the engine
- Hold the odometer reset button until the service engine light starts flashing and reset comes up in the dashboard display
- Cycle through the different service items by pressing the odometer button once to move to the next item.
- Once you get to the required service item, press and hold the odometer button again until the word ‘reset’ appears in the display.
- Press and hold the odometer button again to ‘reset’ the service light. A tick will appear in the display after a few seconds.
- Turn off the ignition and turn it on again and start the engine.