Resetting the ECU

[redlegacygt]

I cant for some reason remember the process of resetting the ecu so whats the process? i know its been said around here before, but cant remember where... Looks like my memory loss is getting worse......

[The Speed Factor]

disconnect the battery terminals for 15 min. Hit the brake pedal a few times to purge the system too. Reconnect, and poof!

[redlegacygt]

good deal, thanks for the info :D

[2.5GT]

just curious, will the alarm go off?

[Wiscon_Mark]

when you reconnect? dunno for sure, but the door locks tend to do weird things. I don't see why the alarm would go off honestly, but you can be ready with your keys just in case.

[The Speed Factor]

Might if the car was shut and locked when you did it, but most of the time when you are doing this kinda thing you have at least the drivers side door open during the process.

[gil_ong81]

i disconnect just the -ve (black) terminal and let it sit for a little (like 15 - 20 min).

with the doors locking, i think a lot of it depends on what kind of alarm etc you have. some will, others won't. safestest bet, like mentioned above, is to keep a door or at least a window open.

[ooberdoob]

yes the OE alarm will go off, have you button ready.

and DER leave the door open. or window down.

[2.5GT]

cool, good info.

[GrassyKnoll]

or do this:

go underneath steering wheel, connect the 2 green plugs that are not connected together.

turn the car ignition on (BUT DONT START THE CAR). put the car in 3rd gear and hold down the gas for a good 10 seconds.

then start the car with the cables still connected (you will get blinking check engine light but no matter), drive around for a good 5 min or so for good measure, turn the car off, disconnect the cables

:)

[ooberdoob]

or pull the cable





:lol: +1 for bein lazy!

[Oliver97GT]

Stupid question: What is the purpose of resetting the ECU?

[Wiscon_Mark]

Stupid question: What is the purpose of resetting the ECU?

The ECU stores the CEL codes. To make sure your problem isn't just a little glitch, you reset it and if the code comes up again you have a problem.

Another thing to keep in mind, is if you modify, say, your intake, then it's going to sense that something is wrong (just different), and it'll probably throw a code. You reset the ECU, and it relearns the new intake, erasing the code, and making the intake system more efficient.

[Plays_with_Toys]

Stupid question: What is the purpose of resetting the ECU?

The ECU stores the CEL codes. To make sure your problem isn't just a little glitch, you reset it and if the code comes up again you have a problem.

Another thing to keep in mind, is if you modify, say, your intake, then it's going to sense that something is wrong (just different), and it'll probably throw a code. You reset the ECU, and it relearns the new intake, erasing the code, and making the intake system more efficient.

And to add, resetting the ECU clears its memory of how you drive the car. So, if you do an exhaust/intake/other power mods, it will learn the new demands of the motor/driver and map the fuel accordingly, allowing you to take advantage of the mods more. If you buy an intake install it, drive, then reset the ecu and see how it changes.

[Oliver97GT]

Cool, thanks for the info. For the last little bit, I've been getting an intermittent CEL. Car seems to drive fine, though. I'll try resetting the ECU.

[shazapple]

Every once and a while Ill get one too. Mostly on a cold morning. I figure its about time to get new sparkplugs and wires.

[CarlitoQC]

after resetting what is the best to drive for the some good ecu learning? how long?

[gil_ong81]

drive normally.

[Wiscon_Mark]

Drive like you always do. That allows the ECU to learn your style and fuel appropriately.

[TGX4776]

wow this is old. lol

So do all the ways work or only one? Can't i just swing by an autozone and have them reset it for free?

[Robbks]

here is the proceudre
http://www.mrtrally.com.au/performance/howresetecu.htm

to make the procedure much easier, i have both sets of connectors connected/ disconnected via a pair of switches mounted under the steering column.
you don;t need to look for them, or have un-sightly wiring hanging down.
they're easy to use from the drivers seat any-time you need to

[TGX4776]

This is the same for USDM and JDM Vehicles? (y'all get JDM right?)

[Robbks]

i'll check the EUDM service manual i have....

EDIT:
the Gen2 EUDM Legacy service manual shows them in the same place.... under the steering column on their respective LHD/ RHD vehicle

[TGX4776]

thanks

[nikolaus.conrad]

Is that the purpose of those green plugs under the steering wheel? I have been wondering what they hook up to now for quite some time.

[nomad666666]

what the plugs do is found here

viewtopic.php?f=10&t=16652 (https://sl-i.net/FORUM/viewtopic.php?f=10&t=16652)

[Robbks]

Connect both sets of plugs (green and black) and follow procedure i linked before for an ECU reset
Connect Green plugs only, then turn IGN to ON to read Trouble codes.

[nikolaus.conrad]

Gotcha, I see now. Thanks!

[MRLancaster]

Where are these black cables at? I only have the green ones on my 3rd gen.