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Can a Bad Car Battery Cause Computer Problems?


A car battery is an essential part of a car. It powers up a car to start and runs all electrical appliances in the car. A bad car battery is bad news, especially for electric vehicles that do not use alternators and can cause problems. Search no further if you’ve ever wondered whether a bad car battery can affect your computer.

The short answer is undoubtedly a YES. A bad car battery can cause computer problems, especially when it does not consistently receive sufficient power. 

This article will provide all you need to know regarding this subject. Read on to learn more!

How does a car computer system work?

A car has various computers called electronic control units (ECUs). Each ECU has several jobs, such as controlling the engine or transmission, unlocking doors, and rolling up windows.

car computer system

These ECUs receive information from sensors and regulate voltage, acceleration at different angles, steering angle, braking, yaw and roll of the vehicle, and several other things.

Information is rapidly shared between different ECUs through sensors to keep the car functioning properly.

How does a bad car battery cause computer problems?

The modern car computer system is the brain of the car. It manages all car systems based on information from various car sensors.

Like every other brain unit, it needs the energy to function properly. It will surely fail if it does not consistently receive enough energy supply.

A bad car battery can not supply the energy required for the proper functioning of the car systems. This will result in various computer problems, which we will see below.

How do you know when your car has computer problems?

The main car computer system is the engine control module (ECM). It controls and ensures the safe performance of the car as it constantly receives information from different sensors and electronic modules. Its primary function is to manage the fuel-to-air ratio and engine timing.

When your car computer system is faulty, you will notice several following.

Jerky acceleration of the car.

The ECM and TCM (Transmission control module) work hand in hand to ensure proper acceleration. The TCM handles shifting while the ECM adjusts the throttle accordingly.

This good cooperation leads to the relatively smooth, effortless shifting you expect from an automatic transmission.

When the TCM shifts properly but the ECM fails to adjust the throttle properly, acceleration becomes jerky. If this persists, you should have your car checked by an expert.

The check engine light randomly comes on.

The check engine light detects any issues that the car sensors fail to pick up. Whenever you check engine light randomly comes on, know that there may be a problem with your ECM.

The running car engine stutters or misfires.

Getting the right fuel-to-air ratio is pivotal for the proper functioning of your car engine. A lean fuel-to-air ratio causes your car engine to stutter when it periodically fails to ignite. On the other hand, a rich fuel-to-air ratio can cause your engine to misfire.

Knowing that the ECM controls the fuel-to-air ratio, a faulty fuel-to-air ratio directly indicates a problem with the ECM.

The car fails to start.

A Car starts when the engine starts. If the fuel-to-air ratio is incorrect, you will probably have to turn your key several times for the engine to turn over. If this happens, you should get your ECM checked.

car won't start for battery problems

The car fails to accelerate even when you step on the breaks.

When your ECM or TCM fails, it will be impossible for you to accelerate your car since they both work together to ensure proper acceleration.

Having seen how much trouble a bad car battery can cause, It is very important to know how to identify it. Replacing your battery on time saves you from a lot of extra expenditure.

How do you know when your car battery is bad?

Car batteries depreciate with use. A bad car battery comes with several signs that make you see that your car needs a battery replacement. Some of them include

bad car battery

Dimmed Lights.

In a vehicle, the car battery powers all electrical appliances. Dim car lights usually accompany a bad car battery. Dim lights indicate that the battery does not have enough charge to power the lights. Any battery that can not keep charge is considered dead.

A slow starting engine.

As your battery ages, it becomes less effective. A failing battery takes a much longer time to power up the engine for the car to start. A completely bad car battery will not be able to power up the engine at all.

Random and Spontaneous Illumination of Multiple Warning Lights.

Any sudden and spontaneous illumination of multiple warning lights and warning messages in your instrument cluster indicates that your car battery is weak. This will probably be accompanied by the non-functionality of various systems, including cruise control, anti-lock brakes, and traction control.

If this happens, have a professional examine the battery and replace it.

Corrosion on terminals.

Corrosion usually occurs when acid spills out from the battery. A low-charge battery with corrosive terminals is probably already bad.

Sluggish or slow crank.

The engine cranks slowly and sluggishly in cars with bad batteries than normal. If you experience this continuously, have a professional check your battery.


If you notice intermittent sparks, get your car battery checked. Dying car batteries can cause intermittent sparks that can result in an accumulation of fuel in cylinders. Ignition of this built-up fuel will cause your car to backfire.

In addition to those, have your battery checked if you notice the following

  • The battery struggles to combat seasonal changes
  • The check engine light randomly comes on
  • A rotten egg smell when you lift your hood
  • You jump-start the car more often than normal

Some other common causes of car computer problems

There are several causes of car computer problems. Some include

  • Poor grounding connections
  • Loose and sparking battery connections
  • Faulty car alternator that can overpower and damage the car computer
  • Old age
  • Exposure to water
  • Bad jump-starting. If you wrongly connect the terminals while jump-starting your vehicle, it may destroy your ECU.

Will disconnecting your car battery harm the computer?

Disconnecting your car battery will not permanently damage your computer. At most, it will reset your ECU.

In some older cars that utilize old ECUs, disconnecting the car battery for a while will reset the ECU.

Disconnecting the car battery may only reset the radio station and clock presets in today’s cars.


A bad car battery can cause car computer problems and electrical problems. Hence, it is best to change your battery at the appropriate time to avoid further damage to other car components.

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