When you change the battery of your VW vehicle, you may need to reset the vehicle’s computer. Start by disconnecting the battery cables and tapping them together.
Keep them disconnected for up to fifteen minutes before reconnecting the cables to your battery. Then, you should be able to start the car.
Table of Contents
- Why Won’t My VW Start After I’ve Changed The Battery?
- How To Reset VW Immobilizer
- Another Way To Reset VW Immobilizer
- Why Else Won’t A VW Starter After Battery Change?
- What Does The VW Immobilizer Do?
- When To Reset A VW Computer?
- What Does The VW Computer Do?
- Do You Need To Reset VW Computer After Battery Change?
- Signs VW Computer Is Bad
- How Much Is A Replacement VW Computer?
- Frequently Asked Question
Why Won’t My VW Start After I’ve Changed The Battery?
After changing the battery of your Volkswagen, you may find that the car won’t start. Unfortunately, this can be caused by a handful of issues.
However, the primary issue is that the immobilizer must be reset. The component plays an important role in the starting process and won’t work until it has been reset.
Usually, it isn’t difficult to reset the immobilizer although there are two or more ways to do it.
How To Reset VW Immobilizer
You may need to reset your VW computer after a battery change. Otherwise, the car won’t start properly. In some cases, the immobilizer will be the problem.
After changing the battery, put the key in the ignition and turn it. Look at the dashboard. Does the immobilizer warning light turn on?
When the light is flashing, the system is warning you that the immobilizer is no longer connected. Therefore, you’ll need to reset it to get it working correctly.
Start by popping the hood and disconnecting the battery cables. Then, you’ll want to tap the cables together.
Don’t reconnect the cables for at least 15 minutes. Once you’ve reconnected the cables, try starting the automobile.
Usually, this will be enough to resolve the problem.
Another Way To Reset VW Immobilizer
If the method above didn’t work, you will need to try something else. Unfortunately, this method takes a lot longer.
First, make sure that the battery is currently being charged. Leave the charger on.
Place the key in the ignition and turn the battery on. Do not turn on the engine.
Let the car sit like this for at least an hour. In some cases, this will reconnect the immobilizer and allow you to start the car again.
Remember that you can always take your car to a Volkswagen dealership to get professional assistance.
Why Else Won’t A VW Starter After Battery Change?
If the vehicle still won’t start, there is a risk that you’re dealing with a different issue. Although it is unlikely, you may be using a dead battery.
Even if you just brought the battery home from the store, it may not hold a charge. It may have been faulty after leaving the warehouse.
Try taking the battery back for a new one. If the battery was the problem, the car will likely start with a new one.
You’ll also want to check the key since it could be bad. When possible, try using the spare key to start the automobile.
If the vehicle starts with the spare, the original key is likely bad. Consider getting a copy of the spare made so you’ll have two.
What Does The VW Immobilizer Do?
The immobilizer on a Volkswagen vehicle is very important. If it isn’t connected to the system, it will prevent the vehicle from starting.
The security device ensures that the car will only start when the correct key is used. It also plays a role in starting the car remotely. When you change the battery, the immobilizer may become disconnected.
Until it has been synchronized, the car will not start. Maintaining a back current when changing the battery can help prevent the computer settings from being lost.
When To Reset A VW Computer?
The computer in a Volkswagen computer must be reset from time to time. If you recently changed the battery or a sensor, it would be a good idea to reset the computer.
The ECM or Engine Control Module is responsible for controlling many engine components. If you notice that the engine light is on, it could be a sign that the computer should be reset.
It could also be telling you that a certain part should be replaced. However, it is best to reset the computer before replacing any components.
With this in mind, it is best to reset the computer each time you change a part.
What Does The VW Computer Do?
The computer in your vehicle is vitally important. The computer and electrical system ensures that the other components and systems can work properly. For instance, they allow electronic panels, alarm systems, radios, and air conditioners to work.
If something is wrong with the computer, the car likely won’t start. Alternatively, it may prevent one of the other systems from working correctly.
Resetting the computer may resolve the problem, but you may also need to take the car to the dealership. A bad computer could cause the vehicle to stall. It may also require ten or more attempts before you can get the car started.
Do You Need To Reset VW Computer After Battery Change?
Your Volkswagen car isn’t going to operate efficiently unless the computer is working correctly. A battery change can throw things out of line so it is wise to reset the computer after you’ve changed the battery.
You’ll also want to reset the computer after you’ve changed any part of the vehicle. It shouldn’t be too difficult to reset the computer, but you need to make sure that you’re doing it correctly.
Disconnect the cables to the battery and tap them together. Leave them disconnected for 15 minutes or longer.
Reconnect the cables and start the car. The computer in your VW vehicle has been restarted.
If you’re having difficulty resetting the computer, consider taking the vehicle to a local dealership.
Signs VW Computer Is Bad
If you’re dealing with a bad computer, you’ll likely notice the signs right away. After all, the ECU is one of the most important components in any vehicle.
A bad computer will cause the car to misfire and the engine to lag. There is also a good chance that the check engine light will turn on.
As the problem worsens, it’ll get harder to start the car. If you manage to start the car, it may turn off unexpectedly.
The fuel economy will drop too. Suffice to say, you do not want to drive a vehicle with a bad computer because it can cause an assortment of problems.
Take the car to a mechanic to find out what is wrong.
How Much Is A Replacement VW Computer?
If your VW computer must be replaced, you’ll find yourself with a hefty bill.
Unfortunately, it can cost up to $1,000 to replace the engine control module in your vehicle. You’ll also have to cover the labor costs.
Be sure to shop around to get the best deal.
Frequently Asked Question
Can I Replace My VW Computer?
In some cases, you may be able to replace your car’s computer without professional help. It may take up to 30 minutes. Just remember that there are risks involved so it may be best to get help from a professional.
Can The VW Immobilizer Be replaced?
Thankfully, you can replace the immobilizer in your Volkswagen vehicle. Make sure that you find an exact replacement because older models may not be compatible with your vehicle. The component is inexpensive and relatively easy to replace.
Is It Easy To Reset VW Computer?
It is easy to reset your VW car’s computer. Disconnect the cables and tap them together. Leave them disconnected for 15 minutes or longer before reconnecting them.
Start the car and your computer should reset.
Robert Bacon is a car nerd and automotive lover who has dedicated his life to understanding the inner workings of vehicles. He holds a degree in mechanical engineering and has spent years working as a mechanic and engineer for some of the world’s top car companies. In his spare time, he enjoys writing about cars on this blog and tinkering with his 2016 Toyota Mirai in his garage.