Risks of Resetting ECU
Thread Starter
Joined: Jun 2004
Posts: 1
Likes: 0
From: Anaheim, CA, USA
Risks of Resetting ECU
Hi Guys,
I just upgraded my intake in my 99 Civic EX Coupe and the instructions say I can reset my ECU but at my own risk. It said to disconnect my negative battery cable for about 5 minutes. Is this accurate and if then what risks can I run into? I would greatly appreciate some assistance on this topic. Thanks for all your help!
I just upgraded my intake in my 99 Civic EX Coupe and the instructions say I can reset my ECU but at my own risk. It said to disconnect my negative battery cable for about 5 minutes. Is this accurate and if then what risks can I run into? I would greatly appreciate some assistance on this topic. Thanks for all your help!
Honda-Tech Member
Joined: Sep 2002
Posts: 2,297
Likes: 1
From: CANADO
I'm guessing the warning may relate to something else, like... work on your own car at your own risk kinda thing... we're not responsible if you fall into the engine bay
but yeah, there is no risk involved... just disconnect the (-) battery terminal and go toss off a batch. when you come back, start the car WITHOUT touching the gas for the first few minutes... once the revs drop (ie. car is in feedback loop) go for a little boot around the block.
but yeah, there is no risk involved... just disconnect the (-) battery terminal and go toss off a batch. when you come back, start the car WITHOUT touching the gas for the first few minutes... once the revs drop (ie. car is in feedback loop) go for a little boot around the block.
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: (jmjmotorsport)
Only downs to resetting the ECU:
1. If you have a factory radio with a code, you will need to have that code ready because disconnecting the negative cable will rest the radio.
2. If you have to pass emissions the ECU will not communicate with the emissions scanner until you drive the car for a a while
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.
1. If you have a factory radio with a code, you will need to have that code ready because disconnecting the negative cable will rest the radio.
2. If you have to pass emissions the ECU will not communicate with the emissions scanner until you drive the car for a a while
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.
Honda-Tech Member
Joined: Feb 2004
Posts: 3,622
Likes: 0
From: The Hudson
Re: (B18C5-EH2)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 »</TD></TR><TR><TD CLASS="quote">
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.</TD></TR></TABLE>
I had asked a honda tech at the dealer how to reset my misfire code after getting a shitty aftermarket dizzy cap wet. I specifically asked how long I needed to leave the neg off to reset the ECU, and he told me the way they do it at the dealer is to take both terminals and touch them together to reset. Tried it, and it worked great, no waiting.
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.</TD></TR></TABLE>
I had asked a honda tech at the dealer how to reset my misfire code after getting a shitty aftermarket dizzy cap wet. I specifically asked how long I needed to leave the neg off to reset the ECU, and he told me the way they do it at the dealer is to take both terminals and touch them together to reset. Tried it, and it worked great, no waiting.
Trending Topics
Joined: May 2002
Posts: 1,166
Likes: 0
From: Peoria, IL, USA
Re: (EX_AutoXer)
why would touching the terminal together do anything? There is no charge with battery not connected? Maybe by the time you disconnect both sides(starting with the negative) and then the positive, touching, reconnecting it would be the time interval if just disconnecting the negative.
If it works it works, ill be doing that after my ECT gets fixed.
If it works it works, ill be doing that after my ECT gets fixed.
Honda-Tech Member
Joined: Feb 2004
Posts: 3,622
Likes: 0
From: The Hudson
Re: (mjrage)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mjrage »</TD></TR><TR><TD CLASS="quote">why would touching the terminal together do anything? There is no charge with battery not connected? Maybe by the time you disconnect both sides(starting with the negative) and then the positive, touching, reconnecting it would be the time interval if just disconnecting the negative.
If it works it works, ill be doing that after my ECT gets fixed.</TD></TR></TABLE>
I have no idea how or why it worked, but it only took me about a minute to disconnect, touch together, reconnect. I checked the codes about a week later, and everything had been cleared.
If it works it works, ill be doing that after my ECT gets fixed.</TD></TR></TABLE>
I have no idea how or why it worked, but it only took me about a minute to disconnect, touch together, reconnect. I checked the codes about a week later, and everything had been cleared.
Honda-Tech Member
Joined: Jan 2002
Posts: 26,519
Likes: 3
From: Los Angeles, CA, USA
Re: (ON-THE-FLOOR4DOOR)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ON-THE-FLOOR4DOOR »</TD></TR><TR><TD CLASS="quote">cant you reset the ecu by taking it unpluging the ecu for a few minutes also?</TD></TR></TABLE>
I heard that you can.
I heard that you can.
Honda-Tech Member
Joined: Aug 2003
Posts: 535
Likes: 0
From: Northwest, WI, USA
Re: (ON-THE-FLOOR4DOOR)
only prob i have ever had with resetting my ecu, is it resets my damn stero, i hate having to go through and redo all the settings! other than that, as all the others have said, i highly doubt there are any other drawbacks..
Member
Joined: Apr 2004
Posts: 1,290
Likes: 0
From: Mission Viejo, CA, USA
The way I learned is disconnect the negative and then press the brake to turn on the brake light and remove all power from the system. Then wait a few min then plug everything back up and let it idle for a few min and then go drive.
Honda-Tech Member
Joined: Feb 2004
Posts: 3,622
Likes: 0
From: The Hudson
Re: (jeffk182)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jeffk182 »</TD></TR><TR><TD CLASS="quote">The way I learned is disconnect the negative and then press the brake to turn on the brake light and remove all power from the system. </TD></TR></TABLE>
I'm assuming that's why touching the teminals together works, by instantly draining all power by grounding all systems together.
I'm assuming that's why touching the teminals together works, by instantly draining all power by grounding all systems together.
Joined: Dec 2001
Posts: 781
Likes: 1
From: Southern, California
Re: (ironballz)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ironballz »</TD></TR><TR><TD CLASS="quote">my helms says to unplug back-up ecu fuse for 3 mins then plug back in.</TD></TR></TABLE>
Thats how i do it. I wonder why techs at honda are telling people to unhook the battery when it states in the honda service manual to pull the fuse.
EDIT: Helms states to only unplug the fuse for 10 seconds.
Thats how i do it. I wonder why techs at honda are telling people to unhook the battery when it states in the honda service manual to pull the fuse.
EDIT: Helms states to only unplug the fuse for 10 seconds.
Joined: Mar 2003
Posts: 194
Likes: 0
From: Madison, WI, USA
Re: (mjrage)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mjrage »</TD></TR><TR><TD CLASS="quote">why would touching the terminal together do anything?</TD></TR></TABLE>
There are capacitors throughout the system which remain charged for a while after unplugging the battery. Especially the relatively large ones in the radio.
There are capacitors throughout the system which remain charged for a while after unplugging the battery. Especially the relatively large ones in the radio.
Re: (B18C5-EH2)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 »</TD></TR><TR><TD CLASS="quote">Only downs to resetting the ECU:
1. If you have a factory radio with a code, you will need to have that code ready because disconnecting the negative cable will rest the radio.
2. If you have to pass emissions the ECU will not communicate with the emissions scanner until you drive the car for a a while
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.</TD></TR></TABLE>
Or you can buy a memory holder and plug it in..
they can be found for like 2.99 at pepboys.
1. If you have a factory radio with a code, you will need to have that code ready because disconnecting the negative cable will rest the radio.
2. If you have to pass emissions the ECU will not communicate with the emissions scanner until you drive the car for a a while
Other than that it's not a big deal really. You can also pull the ECU fuse from the underhood fuse box for a few minutes and it should rest the ECU as well.</TD></TR></TABLE>
Or you can buy a memory holder and plug it in..
they can be found for like 2.99 at pepboys.
Joined: May 2002
Posts: 1,166
Likes: 0
From: Peoria, IL, USA
Re: (jazzman)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jazzman »</TD></TR><TR><TD CLASS="quote">
There are capacitors throughout the system which remain charged for a while after unplugging the battery. Especially the relatively large ones in the radio. </TD></TR></TABLE>
thanks. learning new stuff everyday.
There are capacitors throughout the system which remain charged for a while after unplugging the battery. Especially the relatively large ones in the radio.
</TD></TR></TABLE>thanks. learning new stuff everyday.
Thread
Thread Starter
Forum
Replies
Last Post
