Quick Answer: Will Unhooking Battery Reset The Computer?

What happens if you unplug the ECU?

However, if the ECU is unplugged, it will retain any charge it may have even if you create a power draw someplace else in the vehicle.

So you’d need to wait a decent amount of time to be “sure” it’s drained.

Some folks go so far as to unplug the battery and let the car sit over night..

How do I reset my car after replacing the battery?

Al, I am not sure about foreign cars, but for most US cars, you should connect the battery and then turn the key but not start for about 10 to 15 seconds. Then, once all sensors reset, start the car and just let it sit and idle for 15 to 20 minutes without touching anything. Then all should be fine.

Will check engine light reset itself?

A vehicle cycle is when you start your vehicle and drive it till it warms up, and then you turn the car off. If you are certain that you have resolved the issue that caused your check engine light to come on in the first place, then the light should reset itself after at least 20 cycles.

How do I reprogram my ECU?

Programming overviewConnect the vehicle interface cable to the OBD-II connector and turn the ignition switch to ON.Open the ProECU software and choose Tools then Detect Vehicle.Select Program Engine ECU.Choose Query ECU to identify the ECU version fitted to the car.More items…

Which battery terminal do I connect first?

Connect the positive end first. Attach the red/positive (+) cable to the red/positive (+) battery post and tighten with a wrench. Do the same on the black/negative (-) side. Ensure that the connections on both ends are secure by trying to move the battery around.

Will disconnecting car battery harm computer?

Disconnecting your car battery will not cause any permanent damage to your computer or ECU (electronic control unit), but it can have some adverse effects. Those include canceling your preset radio stations, forgetting learned shift points, and your car’s ideal fuel/air mixture.

How long do you disconnect battery to reset computer?

It’s a real tight fit, but if you can find it and disconnect it, leave it disconnected for 30 seconds.

How do you reset your car’s computer?

How to Reset a Car ComputerOpen up the hood.Remove the positive terminal cable from the battery using your pliers or wrench.Go to your fuse box in your car, and look at the diagram. … Keep the car disconnected like this for two to three minutes to clear the computer’s memory.Insert the fuse back in to the box.

How long does it take for ECU to reset?

Registered. If you don’t want to take my word for it then go to TMO.com and look up resetting the ECU. It only takes like 15 or 30 seconds.

How do you reset an ECU without disconnecting the battery?

Easy Way to Reset ECU without battery disconnect With the key in your pocket/car, push the Engine Start button TWICE (so the car is fully on, but not started) Within three seconds of the car “ON” (again NOT started), Floor (all the way down) and Release the gas pedal fully 5 times within 5 seconds.More items…•

What causes an ECU to fail?

Corrosion and moisture Corrosion or damage due to moisture is one of the main reasons for ECM failure. Corrosion can enter the ECM through the wiring harness and moisture can enter by a failure in the seals in the ECM itself. This happens over a period of time (5 to 10 years) due to the ECMs exposure to the elements.

Which battery terminal do you disconnect to reset computer?

When removing cables, remove negative first, then positive. If you just want to reset the ECU, removing only negative is good enough.

How long do I have to drive my car to reset the computer?

So why is the light still on? Here’s something you probably don’t know: after clearing the car’s computer you will need to drive for about 50 to 100 miles. As you drive your car the computer will monitor all the sensors and register the results.

Can I clear codes by unhooking battery?

Using The Battery Disconnect Method Some late model vehicles will not clear trouble codes by disconnecting the battery. On these vehicles trouble codes are stored in the ECM’s ROM, and only a scan tool will clear trouble code(s) and turn off the check engine or malfunction indicator lamp (MIL).

What happens if you disconnect the positive terminal first?

It can fall across either terminal and the car and nothing will happen. If you disconnect the positive terminal first and you drop a spanner, it is possible for it to fall across the positive terminal and any earth on the car, with spectacular and possible dangerous results.

Is it illegal to clear check engine codes?

Clearing codes is not illegal. Here’s what probably happened. They (autozone) got a nice $500 scanner are while back. When they started pulling codes for free the repair shops that buy from them, who charge for the service, said if you don’t stop we will buy parts from someone else.

Can I just swap ECU?

You totally can install the same model ECU into another car with the same model. However, if the car has an immobilizer, the car will not start until you program the immobilizer to match the VIN on the ECU.