Can a Bad Battery Cause a Check Engine Light to Come On?

Can a Bad Battery Cause a Check Engine Light to Come On

A bad battery is one whose stored energy has been completely depleted. A broken terminal, excessive leaking of battery fluids, discoloration, a crack in the body of the plastic, and many others could cause a battery to be bad but the question is, can a bad battery cause a check engine light to come on?

A bad battery should only cause the battery warning light to come on, but if the bad battery is causing another fault that can trigger the car’s computer system to send a fault code, then the check engine light comes on.

What is a Car Check Engine Light?

The check engine light is one of the most dreaded things that can happen to any owner because it indicates that something is wrong. Nobody wants something to be wrong with their car because they know that it might cost them some money.

The check engine light is also known as the Malfunction Indicator Lamp and as the name suggests, it is a sign that the car’s engine computer sends when there’s a malfunction in the car’s system.

It usually comes on to notify the car owner or whoever is driving when the onboard diagnostics system detects an irregularity in the car’s ignition, fuel, emission, or exhaust systems.

The check light doesn’t necessarily signify a big problem, it could be something as simple as a faulty spark plug or a faulty oxygen sensor, or even when the gas cap is bad or loose.

It could also signify that something severe just went wrong in the car’s system, it could be an engine problem or anything at all as long as it’s an anomaly.

The check light shouldn’t be ignored whenever it zones on because it doesn’t exactly point to a particular thing, so anything could be wrong.

It’s a feature that comes with all cars and it tells the car driver that there’s a problem so it’s best to just do a general check-up in cases when the check light comes on

What Causes the Check Engine Light to Come On?

There’s no specific problem that causes the car’s check engine light to come up. It could range from a fault that you can quickly fix and get on with your journey. It also could be something that will leave you stranded and cause you to spend a lot of money on repairs.

Even though the check light doesn’t point to any problem, in particular, there are a few places you could check real quick to know if that’s where the fault is.

You could do a quick check-up on your spark plug, and check if it’s still functional, you could also clean it and put it back to see if that’s where the problem is coming from.

If you just got an alarm installed in your car, it could be the reason the check light is on. If the alarm wasn’t properly installed, the car’s computer system would see it as a malfunction.

One of the reasons the check light can come on is if your gas cap isn’t properly placed if it’s missing or it’s damaged. If the fuel system isn’t appropriately sealed, it will send a message to the car’s engine computer.

One other reason that is very common among car owners for the check light coming on is a malfunction in the oxygen sensor.

The oxygen sensor measures the amount of unburned oxygen in the car’s exhaust system and when it’s not functioning properly, the car cannot properly measure unburned oxygen so it’s registered as a fault to the car’s computer system.

The mass air flow sensor not functioning well could also cause the engine’s check light to come on. The mass air flow sensor ensures that the right amount of air mixes with fuel for proper combustion.

If this part of your car is not functioning well, a signal will be sent to the onboard computer that there’s a problem with the air and fuel mixture and a code will be generated that will cause the check light to come on.

Every vehicle needs a catalytic converter to function optimally and this can cause the engine check light to come on.

The catalytic converter is an important part of the vehicle’s exhaust system and it is quite expensive to replace, so when it starts getting faulty the system notifies you so that you can make the necessary rectifications so that it doesn’t spoil completely.

Can a Bad Battery Cause a Check Engine Light to Come On?

Usually, when the battery is bad or weak, it causes the battery light to come on but in cases where the bad battery is causing another fault that can trigger the car’s computer system to send a fault code, then the check engine light comes on.

When the battery is bad, it doesn’t supply the right amount of voltage and the car’s computer is getting a low voltage as a result of the bad battery.

The car’s computer is responsible for reporting error codes so when it gets a low voltage, it creates an error code that will activate the check engine light.

Things to Do When Your Check Engine Light Comes On.

Even as much as the check engine light doesn’t point to anything, in particular, there are a few things you can quickly run through to see if that’s where the fault is. There are a series of signals that the engine check light gives.

If you get the yellow, stable check light, you can keep driving and get it checked as soon as possible but if the check light is red or it’s blinking, you should stop driving at once. This indicates that there’s a serious problem with your car.

Tighten Your Gas Cap

As reiterated earlier, the check light could come on as a result of a loose or missing gas cap so you should park your car and try to tighten the gas cap or chicer it properly.

Reduce The Car’s Work Rate

If you’re driving and you notice the blinking check light or you notice any significant problem in the performance of the car, you should reduce the speed at which you’re driving and reduce the number of things the engine is doing.

Check Under The Hood For Signs Of Any Serious Problem

When you notice the red or yellow blinking check light, you could check under the hood of your car to see if there will be any obvious signs of any problem, and if not, get it to a repair shop for a check-up as soon as possible.


A car’s battery can cause the check light to come on and after checking all the places listed in this article and the fault is not from any one of them, you should get your car to a repair shop as soon as possible

Make sure that your car is checked by a professional. Also, remember to always take the check light seriously and the blinking or red light even more seriously.