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Does Jump Starting A Car Damage The Computer? 6 Signs To Know


Drivers are jump starting their modern cars due to a dead battery. A jump start can be your last resort in a desperate situation as a driver.

However, you should keep in mind that this task can lead to mistakes and may cost you. In this post, we will discuss whether or not does jump starting a car damage the computer.

Will The Computer Be Damaged if You Jumpstart the Car With a Dead Battery? 

If you wonder if jump starting a car can damage the computer, the short answer is yes. It can possibly damage the ECU, especially if the jump start is done incorrectly.

ECU, or Electronic Control Unit, also called a vehicle’s ECU, is an essential control system. It gathers information channels to control each element of the vehicle’s engine management and other car function like braking systems, handling characteristics, and climate control.

So, jumpstarting your modern car incorrectly can damage the computer and can lead to bigger problems. It is among the common causes of damaging the vehicle’s electronics, including the ECU.

If you want to avoid damaging the computer as you jump start the car, you should be careful of the polarity of jump leads with a flat battery. Most ECU gets damaged by short circuiting the jumper leads. Make sure to attach the positive leads to the positive and the negative to the negative.

How Can Jumpstarting Cause Damage? 

You may jump start your vehicle if there’s a problem with the engine or car battery. If you’re unsure how the battery died, jumpstarting can cause expensive damage. As you jump start the damaged battery, it can catch fire. A fire in the engine bay is hazardous for your engine and you.

A battery on fire can lead to serious problems since it has sulfuric acid. It turns to vapor and can be inhaled if it catches on fire. Inhaling the toxin for an extended period can cause health problems.

Jumping off your vehicle the wrong way can cause several damages. Additionally, placing the cable ends on the wrong terminals can result in problems. With this, you should know how to jumpstart the battery correctly.

What are the Common Mistakes in Jumpstarting your Car that May Cause Damage? 

The following are the common mistakes of drivers when jumpstarting their modern cars:

Wrong sequence 

Make sure to attach the wires in the correct sequence. If not, there’s a possibility that you can short out the battery cables. You can attach first the positive cables for safety. It is better to have positive ends placed before connecting the negative ends.

Crossing wires

Another mistake when jump starting your car is crossing wires. It can cause an electrical short. With this, you need to check if there are no crossing wires before cranking the working vehicle.

If short happens, it can fry your car’s computer and other electronics. It can give you expensive repair and replacement, which is disappointing.

Skipping the grounding wire 

The negative wire on jumpstarting the working car should be connected. On the other hand, with the dead car, you should connect the broken end to a metal in the engine bay. The cable will serve as a grounding wire. If you don’t follow this step, you can overcharge or short the battery, which can cause damage.

What Are the Things to Consider When Jump starting a Car? 

In jump starting your dead car, you should consider the following factors to avoid mistakes that can damage computers and other electronic components of your vehicle.

Batteries with physical damage or rotten smell are dangerous to jumpstart since they are likely to be dead completely or severely defective. You should not jumpstart a damaged battery.

Use top-quality jumper cables with built-in spike protection.

View your car owner’s manual for jumpstarting your vehicle.

Make sure the leads are connected in the correct poles and correct sequence. Positive battery terminal first, then the negative leads.

Check whether all electrical systems are switched off, such as air-conditioning, lights, and radio.

It is safe to switch off both vehicles and remove the keys from the ignition while connecting to the jumper cables. A possible surge may corrupt coding between the ECU and key.

Is Jump Starting a Vehicle Always Damaging Computers? 

Good news since jump starting cars will not always damage computers. Many factors can affect what level the ECU can be affected. These include the following:

  • Condition of current surge protection mechanisms.
  • Degree of surge protection equipped to your vehicle.
  • The voltage level that is transferred between the cars through cable.
  • Provided the surge will not exceed the capabilities of your systems and you comply with the safety measures.

How to Avoid Voltage Spikes? 

If you connect jumper cables from a running car to a dead battery, the running vehicle’s alternator will put out maximum charging voltage instantly. It can make a voltage spike f about 15.5 volts in both vehicles.

The voltage spike may fry the digital devices and computers. One method to remove the voltage spike is leaving the engine off in the donor car.

Jump starting your vehicle using a jumper pack is also a good option. The jumper start pack battery will boost the discharged battery to a safe voltage. It is the safest way to protect the electronics in the dead vehicle. Here are the steps for using a jumper pack.

First, you can turn off all the electrical accessories and lights of the dead vehicle. Then, connect the cables similar to jumper cables.

Positive clamp first to the positive battery post and the negative clamp to the metallic engine component. Next, you can try to start your vehicle. You can follow the instructions on the jumper pack for best cranking times.

How to Jump Start Your Vehicle Without Any Damage to the Electrical System? 

As mentioned above, there are many ways to jump start your dead vehicle. You need to jump your vehicle correctly to prevent damage. You can avoid damaging the electronic control units with a battery jump box or a proper jump start pack.

The jump box allows the cranking to happen without damaging the alternator or starter. Another option is to jump the car with a car with a good battery. In this case, ensure that the vehicle which provides the jump is off and the key is out of its ignition. In addition, check red to red and black to good ground.

Since the charging system of modern cars is too sensitive, you can’t simply hook up the jumper cables. So, you can do it safely using a new battery box.  Jumper packs tend to work great especially when jumping dead batteries.

Signs That Your Car Computer is Damaged

If you jumpstart your vehicle, it can potentially damage the computer. The following are some signs that the computer is damaged:


Among the symptoms of a vehicle computer damage is misfiring. It occurs if the ECU failed in maintaining fuel to air ratio. However, the misfire is inconsistent.

Increased mileage 

Another symptom is increased fuel mileage. Disruption in air-to-air fuel ratio due to damaged car computers can cause this.

Apparent loss of ignition pulse 

The computers or ECUs are responsible for giving ignition pulse to the motor. If the ECU is not functioning correctly, it may not process the accurate data and will not provide an ignition pulse.

Electric burning smell

The ECU components can burn and wear out because of excessive resistance or load. It can lead to a smell from the control unit.

The vehicle won’t start 

Your vehicle will not start if the ECU doesn’t keep an air-to-fuel ratio and timing belt.

Loss of acceleration 

The vehicle ECU and transmission control unit work as one to keep smooth acceleration and transition. If the ECU is not working properly, it will not send enough or timely data for transmission.

What will happen if the ECU malfunctions? 

The ECU uses enough power wherein it can depend on the alternator to supply for computers and electronic devices’ operation. As you jumpstart, you may be zapping power out, which can make the ECU malfunction and have a shock.

If it malfunctions, it can impact one or more essential computer connections. Additionally, if another car starts up while it is connected to jump cables, it can transfer battery power in the cable to flow back to your vehicle, causing an overflow, also called a power surge.

Surge is hazardous since it can explode the ECU. With this, you need to be aware of not damaging your ECE or car computers to avoid such problems.


Generally, if you jump start your car properly, it may not cause any damage. On the other hand, if you jumpstart your vehicle incorrectly, it can lead to several damages that can be costly.

So, remember that it is crucial to jump start your car properly. The wires should be connected in the proper order, and make sure that they are not crossed to prevent power surges.

These days, newer vehicles are designed with sensitive electronics which are hooked up to the car battery. In this case, you should jump start your car properly to avoid costly repairs.

Last Updated on: February 1, 2023

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