All dashboard warning lights are equally important when it comes to your vehicle’s performance since modern cars have many of them.
A light to be acknowledged is the Service Engine Soon which can indicate maintenance or something else. This light will indicate a warning, yet a full diagnostic will have to be performed to identify the cause.
In this article, we examine Service Engine Soon, its leading triggers, and suggested options for corrective action. Additionally, we evaluate how to take action on the warning, and how to tell the difference between the Service Engine Soon and Check Engine lights.
Last but not least, we cover a few of the burning questions you might have as we near the end of the article so you can make the most informed decisions about servicing your vehicle.
What Does a Service Engine Soon Light Mean?
If your car indicates “service due” or says “service engine soon” on the dash, you can fairly gently take it to someone’s service.
The Service Engine Soon Light which is also known as SES Light, normally comes in red or yellow. In the beginning, that pending light will light up a color that means that a task has not been done with regard to maintenance due – more simply a check.
If you’re overdue and have not taken any action, then your car has a problem that is more serious that will need the attention of a skilled mechanic.
Although the SES light seems very much like a check engine light, so to story spoiler, it is not at all.
Let’s see how.
Service Engine Soon Vs. Check Engine Light
The differences between the two lights are how they look and the type of problem that can be reported.
When the Service Engine Soon lights up, you know it is most likely time for routine maintenance or there is a smaller mechanical issue that needs immediate attention. Again, the Service Engine Soon light is written out in words, “Service Engine Soon.”
The Check Engine Light has an icon that looks like a motor. In some models, it also has the words, “Check Engine.” These problems can vary in severity.
If the Check Engine Light is illuminated and persists, then there may be a minor mechanical issue that may require immediate attention. Not to mention that it may also go off with the possibility of a more serious mechanical problem needing immediate attention.
If the Check Engine Light is blinking, there is even more urgent problems in terms of possible catastrophic damage that can occur if you ignore this light. Meaning you need to pull over and turn off the automobile. You should also never ignore the blinking light!
6 Reasons Your Service Engine Soon Light Is On
Before anything else, a Service Engine Soon or Check Engine light comes on because an issue has taken place. The issue may be something simple that is easily corrected, or deep, complicated, catastrophic issues coming from your engine.
Let’s go over some of the most common ones.
#1. Loose/Faulty Gas Cap.
The first thing to check when the service engine light comes on is the gas cap to make sure it is firmly attached. If the gas cap is not on correctly or there is a minute crack in the gas cap, the fuel tank will then lose vapor or fumes that will cause the ECM to register a problem.
So even if the gas cap did not appear as bad as anything when you first checked it, consider using this scenario to temporarily bypass the check and repair of a weak gas cap gasket, which will obviously produce diminished fuel economy while producing greater gas emissions.
Surprisingly, whether you did not screw it on correctly the last time you went to get gas, or it has damaged, the answer is the same.
These steps should be performed with the engine off and at least half a tank of fuel. First, unscrew the cap and then reattach the cap. As previously mentioned, it usually takes a couple of cycles before the light goes off, and yes, the engine does have to be on and off for a bit.
If you noticed that the indicator has not turned off, at least 30 minutes to an hour after driving, it may be worth buying a new gas cap at your local auto parts store for about 10 bucks.
If a couple of general cycles have been done with no light turning off, there is another problem that needs to be checked.
#2. Scheduled Servicing Items/Low Fluid Levels.
It is not alarming if you are a week or two past due date for an oil change, however if the oil have come to a critically low level, then this will set off an alert. Your scheduled maintenance items like an air filter when excessively dirty will throw the whole system out of balance.
If you are using a car from a specific Make of vehicle, this will mean that your maintenance items along with the check engine, may also give you a check engine oil light, the check low coolant light, or a tire pressure light.
#3. O2 Sensor Failure.
The engine is capable of working optimally. But many things need to be monitored to make that happen: mass airflow sensor, engine speed sensor, spark knock sensor, and coolant sensor. If something happens that puts an engine’s optimal capability in jeopardy, many things can happen.
Next is O2 sensor. The O2 sensor measures the amount of oxygen in the exhaust fumes from the engine. If there is too little oxygen, the engine is ‘running rich’, while too much oxygen results in an engine that is ‘running lean’.
An O2 sensor problem will typically turn the Service Engine Soon indicator on. This happens because the O2 sensor is not able to accurately measure the correct fuel-air balance in the combustion chambers.
This will cause the indicator to turn on. In addition to the indicator light, the affected vehicle will have poor fuel economy, and misfire, or a rough idle.
#4. New Spark Plugs Needed.
The spark plug is a small part responsible for igniting the air and fuel in the combustion chambers of your engine.
You will probably need new spark plugs when you see a reduction in mileage, reduced acceleration, miss firing, difficult engine starts, rough idle or Service Engine light (you guessed it).
Old copper spark plugs would only last about 30,000 miles, but newer plugs such as platinum or iridium-tipped plugs can last up to 100,000 miles or more. If you let them go for too long your engine can stop entirely.
This is a good reason to replace them preemptively at the first sign of trouble since the plugs are only $10 apiece, and with labor you should get all of them replaced for less than $250 at an auto repair shop.
#5. Mass Airflow Sensor Malfunction.
The mass airflow sensor sends information to the ECM about how much fuel is needed based on how much air the engine is getting.
Diagnostic symptoms include a start issue, stalling, a rough idle, or hesitating when accelerating. If it continues to run however, the motor will eventually show you a Service Engine Soon light.
Although you can drive the car with a malfunctioning mass airflow sensor, it is certainly better to not do it for too long. Neglecting this can cause damage and result in a costly repair by destroying your catalytic converter and O2 sensors.
In this case the total costs can average somewhere around $200 to $400 with labor and depend on whether you go aftermarket part or OEM.
#6. Faulty Catalytic Converter.
A combustion engine works using power and gas or diesel, which is a petroleum product, by burning it. If it was pure petrol, then the only byproducts would be carbon dioxide and water.
However, those fuels have are up to 150 more chemicals, increasing the number of pollutants by magnitudes.
This allowed the pistons to move so the shaft could spin and those chemicals can now be burnt to make electricity.
Like any process, there are several moving parts that must be able to operate in conjunction at the same time to produce the final product.
This explains why older vehicles are typically worse than newer models for fuel efficiency.
A catalytic converter facilitates the replacement of these emission exhaust gases, so it will tend to have problems sometime.
If you get a Service Engine Light with the other issues on this list, such as the temp gauge in the red, low performance and lower RPMs and fuel economy it may be advisable for a professional service in regards to your catalytic converter.
A new catalytic converter can cost up to $2000 to replace on new cars. That can make it hard to justify not paying attention to your engine when it starts presenting the mildest issues.
Let’s think about what you can do now that you know about some common causes for the Service Engine Soon light.
How To Fix A Service Engine Soon Light?
Once the Service Engine Light comes on, you want to make time to get your problem fixed as soon as you can. If you let the light fade into the back of your mind, larger problems could rise to the surface, leading to more expensive repairs later down the road.
You can figure out what is going on with your car in a few minutes. Here’s what we recommend.
#1. Check Gas Cap.
If you just left the gas station when the Service Engine Soon comes on, then you want to check your gas cap first. Pull over as soon as is safe to do so, and then pop the gas cover. If the cap isn’t on tight, tighten it and see if the light turns off.
If the gas cap is on tight but you see cracks or imperfections in the cap, you will need a new cap. The same goes if the cap is missing. Luckily enough, you won’t spend more than around $10 for a cap at an auto parts store.
#2. Check And Top Up Fluid Levels.
Next, make sure to check the fluid levels. We will start with the oil. Pull the dipstick and clean it off on a clean rag. Pull it out again and check the level. If it is low, you will add oil. If the oil looks dirty or contaminated, perform a complete oil change and change the filter at the same time.
Once you check the oil now you will check all the other fluids. You will want to check the level and condition of your coolant and your transmission fluid. If either are low or lack clarity, fill them up with acceptable fluid.
#3. Read Trouble Codes.
Every time the ECU sets a fault, there will be codes that will tell you what is wrong. If you are able to use a compatible code scanner, the DTCs will read-you will plug your OBD-II scanner into the appropriate port just under the steering wheel.
Once you have received the code, you will be able to utilize our library of trouble codes to determine what is happening. We have our own separate trouble code resource guide, which will provide assistance defining the more common codes along possible repairs.
#4. Check Service History.
Hopefully you are keeping up with tracking service performed and when. With your service information, there will be an easy determination of what is due based on the current odometer reading.
Perform everything the manufacturer recommends for whatever specified interval you are on. Understand that while your service or maintenance may or may not turn off the Service Engine Soon light, it is helpful to follow along with the service intervals in order to keep the vehicle in running order.
#5. Contact A Professional.
Not everyone needs to attempt to troubleshoot the Service Engine Soon light on their own. If you do not have any kind of experience, or do not have the equipment you deem necessary to perform diagnosis, go to an auto repair shop instead.
Explore the local professionals in your area, receive details on their experience and labor rates. Unless you really prefer a dealer over any of the other shops available, you do not need to go to the dealership and pay higher prices.
What Can You Do to Turn Off the SES Light and CEL?
A diagnostic scan will identify the reason for the issues, as there may be one or several issues in total. It is a fair amount of work because of the knowledge involved with a vehicle’s computer management, so you could need a good automobile service professional for assistance.
Here are a few typical tasks they will do:
#1. Top Off or Change car fluids.
A mechanic will check the engine oil, by using a dip-stick, and confirm the engine oil is full on the dipstick.
When re-filling the tank and confirming fluids such as coolant and transmission fluids, will be in an acceptable range in the tank.
#2. Tighten or Change Gas Cap.
When putting on the gas cap, the mechanic would have turned the cap clockwise until the car made a purring sound, indicating it was a tight seal.
If the cap is cracked, broken, or carted like the rest of the fuel tank, they could apply a more reliable gas cap. The light can also be reset by taking the negative terminal off and back on the battery, to free the code.
#3. Check the Air Filter.
The next procedure would be for the mechanic to safely free the air filter, with as little debris as possible going into the engine compartment.
They then would check to see if the filter was dirty at all by holding it up to the nearest light source to measure if any light passes through it. If no light shined through, they would know for sure that the filter was definitely clogged with dirt. Either way, they normally would install a new air filter.
#4. Check the spark plugs.
The spark plugs would be also taken off for checking for countless issues such as; carbon builders, oil on the spark plugs subject electrodes that have been burnt, and cracks or signs of damage.
Burnt electrodes would also appear black, oily, or encapsulated with soot; and would not only just be cleaned or changed out, they would also have to check the spark plug wires for major damage which has to be no cracks, theft, burn scars on insulation.
The remaining other wires should be checked with a multimeter to determine whether showing voltage as it should.
The multimeter would first need to be set up for the correct ohms scale – such as 50,000 or up. They would attach the probes to both ends of the wire and perform checks along the way till finding the evidence on what the sub check guideline should be as recommended by the manufacture.
If evidence does not match guideline, they than have to replace with all-new wires.
#5. Check the mass airflow sensor.
The last thing would be to check the mass airflow sensor to see how efficient it is operational.
The mechanic should: set the multimeter to voltage mode, and attach the probes; the red would be attached to the signal wire of the mass airflow sensor, and the black would be attached to ground (which is normal at the negative terminal of the battery).
The multimeter should read between 0.5 volts – 1.5 volts with the ignition on, but engine off. If the voltage is less than 0.5 volts or greater than 1.5 volts, the sensor must be replaced.
What is an OBD II Scanner and Why Should I Get One if I Have a Check Engine or Service Engine Soon Light On?
OBD stands for On-Board Diagnostic, and you can get one either at your auto parts store or online for anywhere between $30 to $200.
It doesn’t matter from which price range you purchase yours, they will all do the same thing. Some may even include a better, more detailed LCD screen.
Does having an OBD II scanner mean you never have to go to a shop? No, but you can at least discover the source of the problem for yourself.
If the fix is something easy, like an ignition coil, bad spark plugs, or even a gas cap, you won’t have to pay a mechanic to figure out what could have easily found instructions on how to do yourself.
Next step is to find the Diagnostic Link Connector (DLC). You can normally find it under the drivers-side dash close to the steering column, it looks like triangle appear port with 16 pins. If you cannot find it, refer to your manual for the exact location.
After you locate it, hook up the OBD II scanner with the ignition in the accessory position (do not start the vehicle). It will then ask for some information, like the Vehicle Identification Number (VIN), make, model, and engine type.
Depending on the scanner you buy, the procedures will vary. Nevertheless, you will want to get the scanner to the “codes” menu. You will see a couple of codes. Every code will start with a letter.
(P) for powertrain, (B) for body, (U) for undefined, and (C) for chassis. The letter will be followed by a series of numbers that will indicate the make of the vehicle, subsystem affected, and what the issue is.
It can be confusing at first if you have never used one before, but thankfully you can look up any specific code online to discover what it means. Here is a few of the most common.
Feeling Better About That Service Engine Soon Light?
No one ever wants to find out there is an issue with their vehicle. That being said, even though an Service Engine Soon or Check Engine light is never a good sign, don’t panic, it doesn’t always mean you have a catastrophic problem, it simply means you have found a notification that indicates you need to check on your vehicle.
If you find out what the issue is when it first appears, and get the problem fixed before it becomes a costly problem, you will save yourself time and money, and ultimately feel much better about your vehicle. on the road to live another day.