What Does The Service Engine Soon Light Mean [Causes & FIXED!]

Ever seen a light on the dash which suggests that your car needs servicing? Or a check engine light that is constantly displayed? While there is no good reason to ignore it, it is known to scare many car owners. However, one must first know what a service engine soon light is.

A service engine soon light appears on the instrument console of the dashboard in red on orange color. For a few brands, the light actually reads ‘Service engine soon’ while for many others, an engine symbol turns on. There are two reasons for the light to show up. 

You’ve either skipped on a scheduled service that was due in the recent past or, there is a minor problem in the car that needs attention. So, in case you’re worried because of the service engine soon light, you should probably calm down and read on to solve the problem.

But before we move on, the difference between a service engine soon light and a check engine light must be understood in detail.

Difference Between Service Engine Soon Light and Check Engine Light

While many manufacturers use the same symbol for a “service engine soon” warning and the “check engine” warning, there are many others who clearly differentiate between the two.

If your car uses a common symbol for both warnings and if you happen to see one on the dashboard, it is best advised to stop the car and tow it to the workshop.

The service engine soon light usually hints at a service interval that is overdue or, it could hint at a minor problem in the engine that needs rectification. It is an indication that the engine is not performing in a normal way and the light will remain on until the problem is resolved. 

The service engine soon light could be attributed to an electrical problem or something as important as the engine oil pressure dropping.

On the other hand, the check engine light turns on when there is a major issue in the car, suggesting that the issue demands urgent attention. In such cases, it is usually advised to park the car and tow it to the nearest workshop instead of driving it any further when the.

A check engine light could also indicate problems in one of the cylinders, a non-working oxygen sensor, ignition system failure, or a problem in the fuel system.

Why Is My Service Engine Soon Light On: What Causes It?

Though the problem could be a minor one, the service engine soon light could indicate the following problems in the car:

Cause 1: Service Overdue

If you’ve skipped a scheduled service in the recent past and have forgotten about it, your car could display the service engine soon light as a reminder. This usually occurs if you’ve covered more distance than what is recommended between oil changes. 

Cause 2: Low Oil or Coolant Level 

This is one of the most common causes for the service engine soon light to turn on. A significant drop in the oil level or the coolant level can trigger the light to appear. This should be the first parameter to be checked in case you witness the service engine soon light.

If you notice a drop in fluid levels, it would be advisable to either tow the car to the nearest workshop or, to top up the fluid level and drive to the nearest workshop. 

Cause 3: Adulterated Fuel 

If the car’s fuel has been contaminated for whatsoever reason, the car will display the service engine soon light. The extent of the damage that will be done to the car will depend on the level of contamination. It could damage the injectors and, in some cases, the cylinders too.

Cause 4: Problematic Mass Airflow Sensor 

The mass airflow sensor measures the amount of air that should enter the engine for combustion. If this sensor encounters a problem as a result of a fault, the car won’t know how much air it needs to keep going. Hence, one will notice the service engine soon light on the dashboard. 

Cause 5: Old Spark Plug

An old worn-out spark plug could very well be the cause of a service engine soon warning. Recall the last time it was replaced and you’ll know for sure if it has crossed its replacement due date. Not only spark plugs! Even a fault or inconsistency in the wiring harness can trigger a service engine soon warning. 

Cause 6: Faulty oxygen sensor 

The oxygen sensor is responsible for maintaining the right amount of air-fuel mixture and communicates constantly with the car’s ECM or ECU in the same regard.

A faulty oxygen sensor could trigger a service engine soon light due to an imbalance in the air-fuel ratio which can lead to a considerable increase in fuel consumption, a drop in engine power, or even cause an increase in exhaust emission. 

Cause 7: Catalytic Converter problems 

A car’s catalytic converter plays a significant role in reducing the number of harmful gases that are emitted from the exhaust. Catalytic converters are tough so they last long. 

But, a faulty unit could cause the service engine soon light to turn on since it can lead to an increase in engine temperature, thereby compromising the overall performance of the car. 

Cause 8: Fuel Filler Cap issue

While it may sound too futile to be true, an incorrectly closed fuel filler cap or a damaged one can cause the service engine soon light to turn on. The fuel filler cap is designed to keep the fuel tank airtight. 

 In case of a faulty fuel filler cap, the car’s computer would detect an air leak in the fuel tank, thereby triggering the service engine soon light. 

How to Diagnose The Problem? 

Considering the causes listed above, there are a few of them that you can check yourself to ascertain the source of the problem. For the rest, it would be best to seek professional help since it involves the use of diagnostic and precision tools to get to the root cause of the problem.

1. Manual Diagnosis

Checking the fuel filler cap and ascertaining the oil and coolant levels are something that almost anyone can do. To check if the fuel filler cap is the reason for the service engine soon light, switch off the vehicle and take off the fuel cap.

Have a good look at the rubber seal that surrounds it. Scrutinize well for any cracks or damages that could cause the air to leak. Fix it back tightly and then turn on the car. Drive it for a few miles to see if the service engine soon light turns off. If it does, then an incorrectly closed fuel filler cap was the culprit.

Similarly, with the help of the dipstick, one can check if the level of engine oil has dropped. The car’s user manual would be a good guide to knowing the level of oil that should be indicated on the dipstick.

Once the dipstick is located, check the level of engine oil indicated on it. If it is below the minimum mark, a top-up must be done immediately to avoid any possibility of further wear and tear in the engine. After topping up, switch on the car to see if the service engine soon light has disappeared.

Similarly, the coolant level can also be checked manually to see if that is the cause of the service engine’s soon light. All one has to do is locate the coolant reservoir and ensure that the coolant is not below the minimum mark. If it is, then the coolant must be topped up. Once that is done, the car must be switched on to see if the service engine soon light has turned off.

Despite the fact that fluid levels could be checked manually and topped up to turn off the service engine soon light, the root cause must not be ignored since it is an indication of the engine not working the way it is supposed to. It is highly recommended that the car be inspected by a professional.

2. Professional Diagnosis

Professional mechanics have all the necessary tools required to check the cause of the service engine soon light, including a diagnostic scan tool that connects to the car’s computer and displays the exact source of the problem.

This is perhaps the easiest and fastest way to know the root cause of a service engine soon light, especially for those cars that are heavily laden with electronics. Once the root cause is identified, the mechanic would take necessary decisions pertaining to the error displayed and order parts if a replacement is required.

How To Turn Off The Service Engine Soon Light?

The best way to turn off the service engine soon light is to solve the problem. If you’re looking to turn off the light that came on as a service reminder, then you must know that the method to turn it off differs from manufacturer to manufacturer. We’re listing ways to clear the service engine soon light for each manufacturer below:

1. Nissan Service Engine Soon Light

Plug the code scanner plugin into the OBD2 port before turning on the power but without starting the car. Then click the ‘read’ option so it will display a list of error codes that need to be matched with the code sheet. Repair all the faults after turning the key to the off position. Turn the key back to the ‘on’ position and press the ‘Erase’ button to clear the codes and reset the computer.

2. BMW Service Engine Soon Light

Turn on the car’s electrical system without starting the car. Press and hold the small odometer button until the service message appears. Release the button before pressing and holding it again. The computer will flash ‘Reset?’. Release the button and hold it again until it flashes another message saying ‘Reset Successful’. You may then reset the car and start it again to ensure that the light was reset successfully.

3. Mitsubishi Service Engine Soon Light

You will need a scanner to reset the service engine soon light. Plug the code scanner into the OBD2 port before turning on the power but without starting the car. Select the ‘Read Codes’ option on it. Turn the key to the off position and match the codes with a codes manual. Rectify the errors. Once done, turn the key back to the ‘on’ position and select the ‘Clear Fault Codes’ option to reset error codes.

4. Infiniti Service Engine Soon Light 

Use an OBD2 scanner and plug it into the OBD2 port. Turn on the car but without starting it. Select the ‘Read codes’ option so it will display a list of error codes that need to be understood using the manual. Rectify all the faults after turning the key to the off position. Once done, turn the key back to the ‘on’ position and select the ‘Clear Fault Codes’ option to clear reset Infiniti check engine codes.

5. Chevy Service Engine Soon Light

Resetting the service engine soon light on a Chevy can be done with the help of a scan tool. Plug the OBD2 scanner into the DLC port below the dashboard. Turn on the key without starting the car. Allow the scan to look for codes. Refer to the manual to understand them and have the car repaired after turning off the car. Once done, plug the scanner back and select the ‘Erase Codes’ option. 

6. Ford F150 Service Engine Soon Light

Many users have reported that disconnecting the battery for a few minutes and reconnecting it clears the service engine soon light. If that doesn’t work, one can use the OBD2 scanner and link it to the port to scan for codes. Make a note of the codes and have the repairs done to the truck. Re-connect the scanner to erase all the codes. This should help get rid of the service engine soon light.

FAQ’s

Why is my service engine soon light blinking?

A flashing service engine soon light would mostly hint at a serious problem in the car that would need professional assistance urgently. It would be best to tow the vehicle to the nearest garage.

Can you drive with the service engine soon light on?

Yes, you can drive your car for a while if there are no obvious signs like a drop in engine power. However, you must ensure to know its root cause and fix the same, at the earliest.

Does Autozone check the service engine soon light?

Yes, Autozone would help you know the reason behind the service engine soon light.

Can low oil cause the service engine soon light?

Absolutely! As mentioned in the causes above, a drop in engine oil level can trigger a service engine soon light.

Is the service engine soon the same as the check engine light?

No, a service engine soon light could be a reminder for you to get the car serviced or it could indicate a minor problem that needs fixing. The check engine light however hints that your car is having a serious problem.

Can low coolant cause the service engine soon light?

Yes, a drop in coolant level could cause the service engine soon light to turn on.