Does Jump Starting a Car Damage the Computer?

Does Jump Starting a Car Damage the Computer?
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A dead car battery can be very frustrating to any motorist. Not only are they inconvenient, but they also come with the cost of replacing the battery. While any unforeseen cost is undesirable, the cost of jump starting your car could involve much more than just a battery replacement.

Most cars manufactured after 2000 use many computers and computer functions that have developed and become more advanced as time has progressed. These machines control various common functions in the vehicle ranging from the dial cluster to the radio. In this article, we will explain what happens when you jump start your car and the effect it can have on the electronic and computer components in the car. Let’s jump into it and take a look.

The Risks of Jump Starting

Technological improvements in manufacturing and the growing shift from gas to electric engines have seen computers become a major element in car building. Computers in your vehicle are responsible for functions as simple as opening your windows to something life-saving, like controlling the brakes in your car. These computers are controlled by one or many electronic control units (ECUs), which act as the brain for these computers.

Like the body, any sudden shock will cause your brain to react negatively. For example, if you’ve seen someone being tazed before, you would notice that the shock causes the brain to malfunction, affecting everything it controls. That’s when you notice the person shaking uncontrollably, or worse.

This is pretty much the same logic when jump starting a car. The ECUs work steadily, using a specific amount of power which it can rely on your alternator to supply to operate all the computers and other electronic devices in the car. When you jump start, you are zapping power out suddenly, which can cause the ECU to go into shock and malfunction. A malfunctioning ECU can affect one or more critical computer connections.

In addition, once the other vehicle starts up while still connected to the jump cables, this will cause the moving power in the cable to flow back to your vehicle, which can cause an overflow, commonly known as a surge. Surges are very dangerous as they can cause an ECU to explode if it is unable to dump the surplus power effectively.

Auto mechanic in red uniform diagnosing car with computer

Important Points to Remember When Jump Starting

  • Batteries that have physical damage or are giving off a rotten smell are not safe to jump start as they are likely severely defective or completely dead. Never jump start a damaged battery!
  • Check your vehicle owner’s manual for instructions for jump starting your vehicle.
  • Always use high-quality jump cables that have built-in spike protection.
  • Ensure the leads are connected in the correct sequence and to the correct poles. Positive poles first, then negatives!
  • It’s safer to have both vehicles switched off and the keys removed from the ignition when connecting the jumper cables. Any potential surge can corrupt the coding between the key and ECU.
  • Check that all electronic components are switched off, including lights, air-conditioning, and the radio.

Does Jump Starting Always Damage Computers?

The short answer is no! Several factors influence to what level the computers and ECU may be affected, including:

  • The degree of surge protection that’s built into your vehicle.
  • The condition of the existing surge protection mechanisms.
  • The level of voltage being transferred between the vehicles through the cable.
  • Provided the surge does not exceed your systems capabilities and you follow the safety pointers mentioned above, your computers and ECU should come through the jump start unscathed.


Jump starting vehicles is a task that any motorist is likely to encounter at some point in their lifetime. Even if not for your own vehicle, you may need to help someone, and knowing how to do so as safely as possible makes sense. It could also save you from costly repairs that can arise from breakdowns caused by jump starting cars with computer components.

Be sure to check the condition of the battery you are connecting to and take the necessary steps to manage the surge of power. This will help minimize the risk of severe damage being caused to both vehicles.


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