As you continue to use it, your truck will eventually need maintenance. No one wants to see the dreaded check engine light appear on their instrument panel, but it’s always good to know what the light indicates so that you have an idea how to fix the problem. Here’s everything you will need to know about the check engine light flashing.
When a check engine light is flashing, there is a critical malfunction in your engine that needs rectifying. When the light flashes rather than just being on, it indicates a serious failure of an engine, transmission or an electrical system component The vehicle should not continue to be driven and should be take to a mechanic as soon as possible. The code provided over the OBD2 port that can then be translated into human language will provide more detailed information about the issue.
There are a number of causes for the check engine light to appear, and the most important thing to remember is that if you see this warning on your panel, don’t ignore it. The rest of this article will walk you through the various meanings of the check engine light and how to fix it.
What Does the Check Engine Light Indicate?
The check engine light, known formally as the malfunction indicator lamp (MIL) is a signal emitting from the pickup’s engine to indicate that something is wrong with the engine.
There are a number of sensors measuring temperature, pressure, oxygen, and injectors, among other things. When these sensors detect something amiss, the onboard computer turns on the check engine light, which is usually amber or red in color and depicts an engine.
Don’t confuse this with the service required light, which means something entirely different. A service required light only means that your vehicle is in need of an oil change or other minor repairs. More often than not, the check engine light indicates a more serious problem.
An Intermittent Flashing
Depending on the cause of the problem, your light may flash intermittently only when certain problems arise. As an example, loose connections or faulty wiring can continuously connect and disconnect, causing the engine light to trigger and then turn off again. Thankfully, this kind of engine trouble is often the easiest to manage, but certainly still shouldn’t be ignored.
It is best to stop by a local auto parts store and see if you can borrow a code reader to get more info. Most of the auto parts stores loan out tools for free and the OBD2 reader is one of the tools you can borrow. Sometimes they are not easy to use so you can either read the included instructions or ask one of the store clerks to help you figure out how to use it.
Steady Signal
If the check engine light has come on and shows no signs of leaving, then there’s something in your engine that’s not operating within acceptable parameters. In most cases, a steady signal from your engine light reflects that something is not working at all.
In the best-case scenario, it could be the sensor itself that’s dirty or failing, causing it to send a reading to the computer that isn’t accurate. Most of the time, however, a steady engine light will necessitate some fresh replacement parts.
Unfortunately I have one of these in my truck right now. I need to get it taken care of and I just cant seem to find the time for it. I rarely drive this truck so it is not too big of a deal. Also I know that the engine is fine and it is probably something that has to do with some accessory or exhaust sensor that is acting up.
Persistent Flashing
If your engine light starts to flash incessantly, it means that there is a critical problem that needs addressing right away. Most often, a persistent flashing is caused by a misfire allowing fuel to pass into the exhaust manifold and through the catalytic converter.
In just a short period of time, this misfire can cause serious damage to several key systems in your car. Take your car straight to the mechanic if the check engine light starts flashing wildly.
Check Engine Light Meaning For Each Manufacturer
The Meaning Of The Check Engine Light In A Chevrolet Or GMC
The Chevrolet cars and trucks have a check engine light but it is not too detailed about what is going on with the engine other than just letting you know that there is an issue and you need to take the truck into the shop to get it checked out.
If the light is on, means something is going on, if it is flashing, it means you better get there asap. If you are able to get a hold of an OBD2 reader you can find more details on the meaning of the codes for Chevrolet in this article and for GMC in this article I found that will help you narrow down the problem.
The Meaning Of The Check Engine Light In A Ford
Ford uses the Check Engine Light to show that there is a problem, but noting else can be pulled from that. If the light is on, you know there is something going on, and if it’s flashing then it means that something is really bad and needs attention as soon as possible.
Here is a complete list of Ford check engine codes for Ford that will give you more details if you are able to get your hands on an OBD2 reader and pull out the codes that it’s throwing.
The Meaning Of A Check Engine Light In A Dodge
The Check Engine Light in a Dodge indicates a problem and a flashing check engine light tells you something is very wrong and needs immediate attention. The problem can be as simple as a loose gas cap to as critical as a blown head gasket.
If you are able to get an OBD2 Reader tool, you can refer to this article to identify the code the tool gives you to what is actually going on with your engine.
The Meaning Of A Check Engine Light In A Toyota
The Toyota vehicles use the Check Engine or Service Engine Soon light to indicate that something is going on with the engine and it requires attention. When the light flashes it tells you that there is something very wrong and you should take the vehicle to the mechanic as soon as you can.
The vehicle manual says the Malfunction Indicator Lamp indicates malfunction in:
- The emission control system
- The electronic engine control system
- The electronic throttle control system
- The electronic automatic transmission control system
The vehicle has an OBD2 port that you can plug in a reader and pull the codes that the engine is throwing so you can find out more details about the trouble. Here is a list of codes and their meanings that you can refer to.
The Meaning Of A Check Engine Light In A Honda
Hondas use the Check Engine light to indicate a problem in the engine just like most other cars and trucks. It is a common way to alert the driver to a problem that needs attention. This light will light up if there is something wrong in the engine, transmission or electrical system. It will also flash if there is a critical issue that needs an immediate attention.
Hondas also have a method of flashing the check engine light a certain amount of times to indicate a specific issue without having to use an OBD2 device to read the code. This is only used for reference and not to diagnose a problem.
If you have an OBD2 reader you can use this document to find the code and find out what it means.
What to Do about the Check Engine Light
Before you do anything else, start with the basics. If your gas cap is loose or you forgot to put it on, then it can trigger the check engine light. Adjust your gas cap so that it’s nice and tight and try driving the car again. It may take a little while for the check engine light to disappear, but if it does, then that was likely your problem.
In almost every other circumstance, it’s wise to take your car to the mechanic to see what’s wrong with it. Other than fixing faulty wires or loose connectors, it’s not feasible to fix engine troubles by yourself unless you have a good deal of mechanical experience.
What you should never do when you see this light is stick a piece of tape on it and hope it goes away. The check engine light will only turn on when there is a problem that the engine cannot rectify by itself and needs maintenance.
Regardless of whether your light is flashing or steady, it’s important to have repairs done where needed so that the problem doesn’t worsen over time.
Deciphering the Code
If you are a DIY kind of person, then you might be interested to learn that you can figure out the cause of your engine troubles with a little bit of sleuthing.
Since 1996, automakers have standardized their systems for diagnostic trouble codes under a protocol called OBD-II. These codes are readily available if you have a code reader and connect it to the onboard diagnostics port.
Engine Light Help allows you to take the code you get from the code reader and discern what the problem with your car might be. It’s important to note that this method isn’t a cure-all for engine troubles, and a professional diagnosis is always better.
Sensors are prone to breaking down over time, which is why you might want to rely on the pros to take a thorough look at your engine when your check engine light comes on.
How Much Does Fixing the Check Engine Light Cost?
Part Needing Replacement | Estimated Repair Cost |
Catalytic converter | $1400 |
Oxygen sensor | $250 |
Spark plug | $400 |
Mass airflow sensor | $330 |
Loose fuel cap | $25 |
As you can see, a lot of common check engine light issues aren’t too expensive, but it’s important to have your sensors and faulty parts fixed as soon as possible to avoid further damage to your vehicle. Oh, and check your fuel cap to potentially save yourself an easy $25.
Final Thoughts
There are a lot of reasons your check engine light may be flashing, but regardless of the reason, it’s always worth taking your car in to be serviced as soon as you noticed. A minor issue today can result in major damages or even the risk of injury tomorrow if you continue to drive with a faulty engine.

Valik loves tinkering in the garage and is currently restoring a 2000 GMC Sierra 1500 truck. He also writes about the progress on this blog. When not in the garage, Valik is also a web developer and a blogger. I know, strange, a hand in two completely different worlds. And that is the way he likes to keep it.