I was just curious if I could reset the check engine light by disconnecting the battery. I thought I read somewhere that disconnecting the negative termainal for 24 hours or something would erase the codes from the ECU. Has anybody done this before? Don't you also have to disconnect the battery when a high flow intake is installed too?

 

yes you can. But you can also do it in 5 seconds using the screw on the ECU.

 

Here's my opinion based on reading the factory service manual.

To erase the ecu memory, you need to unplug the battery for 24hr or more. That does not mean 3hr or overnight...24hr is 24hr. More is better of course.

The ecu takes measurements from the past 24 or 27 (i forget) engine starts from cold engine to normal operating temp. So if you drive the market a few blocks away, buy stuff, then drive home, that will not be factored into the ecu's learning curve. It's gotta be: wake up in the morn, drive to work many miles away till car is @ normal operating temp. Park car until it's time to go home many many hours later (sure sounds like many of us do this anyways!). Then drive all the way home and park while car is still warm. That will count as 2 learning steps.
To be safe, I tell people it takes at least 2 weeks for the ecu to learn. That means, when you add a mod and your butt dyno says you gained HP, you'll either get used to the mod and not feel it after a month, or the ecu learns the mod and "cancels" it out by adjusting itself. You don't hafta reset the ecu after each mod...doesn't make a diff either way cuz it'll still take 2 weeks for the ecu to learn it.

Jae

 

I don't think you know what you're talking about.

 

You can reset the ECU by using the screw on the side of the ECU box next to the gas pedal. Much simpler than disconnecting the battery, and you won't lose your radio presets either.

 

insert...turn it...

then turn it...watch the lights...turn it... remember the lights.

or go here http://www.vbxmaxima.8m.com/ecu.html

 

and you've successfully checked your codes

to reset, turn right to stop, left to stop, wait a second, turn right to stop, left to stop....congrats

oh btw, right = clockwise, left = counterclockwise