If your car computer is faulty you will experience engine performance issues, check engine light will display on your dashboard or your car engine may not start.
To fix these issues you can reset your car computer to its default format without disconnecting your car battery.
Here in this article, learn how to reset car computer without disconnecting battery by simply locating the fuse box and removing the computer fuse.
How To Reset Car Computer Without Disconnecting Battery
Follow the steps below to learn how to reset car computer without disconnecting battery:
Turn Your Car Off
Turn your car off your car engine and remove your car key.
Locate The Fuse Box
Open the hood and locate the fuse box. You can find the fuse box behind the car engine.
Remove The Computer Fuse
Open the fuse cover. Then locate and remove the ECU/ECM fuse.
Wait For Few seconds
Leave the fuse out for about 10 to 15 seconds for your car to return to it’s default format.
Return The Computer Fuse
Now return the computer fuse from where it was removed.
Return The Fuse Cover
Don’t forget to replace the fuse cover to prevent damage.
Test Drive your Car
Test drive your car for about 30 minutes. Pay attention to your engine behavior and check to see if the check engine light has been cleared.
How Do I Manually Reset My Car Computer
Manually reset your car computer following the steps below:
Disconnect The Battery
Use a hand wrench to loosen the battery terminals. Locate the negative (-) sign on the battery Then disconnect the negative (-) battery terminal to prevent power from flowing to your car’s computer.
Drain The Electricity in The ECU Box
Turn the headlight switch ON so that the capacitors in the ECU box can drain all the electricity.
Wait For a Few Minutes
Wait about 45 minutes to allow your car computer to return to its default settings.
Reconnect The Battery
Reconnect the negative (-) battery terminal back to the battery compartment.
Run Your Car
Start your car and put the gear in neutral and place your foot on the break. Allow your car to run for about 4-5 minutes in neutral.
Test Drive Your Car
Then take your car for a drive, you need to drive for 20-25 minutes to allow your car to completely relearn the basic things like air intake and fuel injection.
How Long Does A Car Battery Need To Be Disconnected To Reset The Computer?
Disconnect your car battery for at least 15 minutes to perform a full reset to ensure all the remaining power is being drained by the capacitor in the fuse box.
A full reset will allow the car computer to return to its original format. After a reset, your car computer has to relearn the driving process to monitor all the sensors and register the results.
What Are The ECU Reset Benefits
You may want to reset your car computer for a few different reasons. Below are some of the most common:
To Fix Engine Misfires and Stalls
If the engine control unit (ECU) is faulty you may end up with misfiring plugs. You may experience engine idling roughly, sputtering or Stalling.
To Clear Check Engine Light
The warning light in your car’s dashboard is controlled by the ECU. When the ECU begins to malfunction this will throw the check engine light on. Disconnecting the battery terminal will reset the ECU.
To Improve Fuel Economy
A faulty ECU can prevent your engine from getting enough fuel. It can also allow your engine to be getting too much fuel thereby increasing your fuel consumption.
Resetting the ECU will help to improve fuel economy and prevent your car from lagging or stuttering.
To Improve Engine Performance
Resetting the ECU helps in clearing out all of the stored data and returning the computer to its original state thereby improving your engine performance
To fix a Car That Won’t Start
If the ECU is dead you won’t be able to start your car after stopping and you may end up parking it. You should replace your dead ECU or have it reprogrammed by a dealer.
How Long To Leave Battery Disconnected To Reset Car Computer
Leave your car battery disconnected for at least 15 minutes to fully reset your car computer to prevent power from flowing to your car’s computer.
You can loosen the battery terminal using a wrench to loosen the negative (-) battery terminal. To determine the negative terminal, look for the negative (-) sign on the battery terminal.
Will Disconnecting Battery Reset ECU?
Disconnecting your car battery and removing the ECU fuse will allow the capacitors in the ECU box to drain the remaining power thereby causing a reset.
How Do You Reset The ECU By Pulling The Fuse?
Step 1: Turn your car off.
Step 2: Open the hood and locate the fuse box behind the engine.
Step 3: Open the fuse cover., then locate and pull out the ECU/ECM fuse.
Step 4: Leave the fuse out for about 10 to 15 seconds.
Step 5: Return the ECU fuse
Step 6: Replace the fuse cover to prevent damage.
Step 7: Test drive your car for about 30 minutes.
How To Reset Car Computer By Disconnecting Battery
Follow these steps to reset your car computer by disconnecting battery:
Step 1: Use a wrench to disconnect the battery to prevent power from flowing to your car’s computer.
Step 2: Drain the electricity in the ECU box.
Step 3: Turn the headlight switch ON so that the capacitors in the ECU box can drain all the electricity.
Step 4: Wait about 15 minutes to allow your car computer to return to it’s original format.
Step 5: Reconnect the negative (-) battery terminal.
Step 6: Run your car to run for about 4-5 minutes in neutral.
Step 7: Test drive your car for 20-25 minutes to complete the relearn process.
What Fuse Do I Pull To Reset The Check Engine Light?
Pull out the ECU/ECM fuse out of the fuse box to reset your car to its original format. This helps to reset the check engine light.