How to reset a check engine light on 1999 Toyota Camry 4cyl.

[harkauto]

I completed some work on my 1999 Toyota Camry 4 cyl and I'm wondering if there is a way to reset the computer and check engine light without the special tool. Someone said to remove the ECU fuse and turn the key to the Accessories position for 3 minutes, turn the key back to the off position and then re-install the ECU fuse. Another person said to disconnect the negative terminal on the battery and turn the key to the START position and hold it for one minute and then reconnect the battery.
I found that neither of these methods worked.
Another person told me that the only way to reset the check engine light....even after doing repairs is with one of the hand held engine code reading devices.
They said the computer will hold and remember these codes and reactivate the check engine light again even if the repair has been done correctly. They said the code MUST be reset with this tool.
Does anyone out there know if there is actually a way to do this without the tool?....and if so, how?

Thanks for your advice.

[aleekat]

None of these say to accessory, the on position.
https://www.google.com/search?rlz=1C....0.MPZRsefHSy4

[harkauto]

[quote=aleekat;7205563]None of these say to accessory, the on position.

Thanks for your reply. This has been very helpful. One of the instructions I read said to turn the key to position #2 which was not very clear instruction. I interpreted that to mean the accessory position since I figured I was already in position number 1 and to me position #3 would be the start position.
The instruction you provided is very well written.

[Crvett69]

Most auto parts stores will check the codes and reset light for free

[aleekat]

Originally Posted by Crvett69

Most auto parts stores will check the codes and reset light for free

My local auto parts will read the code but won't reset any light.

[harkauto]

Originally Posted by aleekat

My local auto parts will read the code but won't reset any light.

My local store won't either. They will read it but not re-set it. Maybe it's some kind of liability issue or something.
However, I was able to reset it myself. I disconnected the negative terminal on the battery, removed the ECU fuse and turned the ignition to the "ON" position and left the doors open for about 30 minutes. I figured all of this would drain off any residual current within the cars electrical system. I then did all this in reverse order and ....PRESTO! No more engine warning light.

[harkauto]

I was working on my MAP sensor the other day. I did a couple of tests to make sure it was working properly.
It passed the tests and I put it back together and closed the hood for the night.
The next morning I started the car to go somewhere and found my check engine light was on when it had not been on the day before.
I figured that I must have triggered a code by disassembling the MAP sensor assembly the day before and told myself that I would reset the computer and clear the dash light later when I got home.
Much to my surprise, while I was driving the dash check engine light went out all by itself and I didn't have to reset the computer or clear the light at all.
So, evidently, if a person disconnects and reconnects a component that might trigger a code, the dash light will just automatically clear itself once the computer discovers that all is well with the system.