Re-setting the ECU
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From: South NJ
Re-setting the ECU
Today i decided to re-set my ECU. After i re-set it the car wanted to die everytime i came to a stop and the car also felt sluggish for about the first 10mins. After that it seemed to run fine.
I think i read on here somewhere that even though the car has been shut off the ECU is still functioning, and that you shouldnt disconnect the battery terminal until the car has sat for about 15-20 mins after shutoff. Well i disconnected the battery about 1minute after i turned the car off.
So i just wanted to get some info to see if i messed anything up.
Hopefully i didnt.
TIA
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From: I live in an ER
Originally Posted by s2000news.com c/o Stookfreak
Resetting the ECU/Check Engine Light
Put the key in and turn to on and then turn to off, leave the key in.
Locate the fusebox - its above your left foot if you are sitting in your S2000.
Locate the fuse - right side of panel, 2nd fuse from top (3rd slot from top). It's the 7.5A fuse that's right between a 15A and a 7.5A. Its marked "Back Up".
Locate fuse pulling tool - its stored about 4 inches to the left nestled in a group of relays.
Pull out the fuse with the removal tool (if necessary), count to ten and stick it back in (key off).
After removal wait for 10-15 seconds.
Put the fuse back the right way, not upside down otherwise it will not work.
Turn the key and start the engine and that should take care of a check engine light and resetting of the ecu. Let the car Run and Idle for 3-5mins. With NOTHING on (no lights, radio, dome light, etc)
If you reset the engine light and it returns, then there can be something wrong with your car. Resetting the light, as described above, is a troubleshooting tip to see if it is merely a glitch in the ECU or perhaps some modification that tripped it off and needs to be reset.
Put the key in and turn to on and then turn to off, leave the key in.
Locate the fusebox - its above your left foot if you are sitting in your S2000.
Locate the fuse - right side of panel, 2nd fuse from top (3rd slot from top). It's the 7.5A fuse that's right between a 15A and a 7.5A. Its marked "Back Up".
Locate fuse pulling tool - its stored about 4 inches to the left nestled in a group of relays.
Pull out the fuse with the removal tool (if necessary), count to ten and stick it back in (key off).
After removal wait for 10-15 seconds.
Put the fuse back the right way, not upside down otherwise it will not work.
Turn the key and start the engine and that should take care of a check engine light and resetting of the ecu. Let the car Run and Idle for 3-5mins. With NOTHING on (no lights, radio, dome light, etc)
If you reset the engine light and it returns, then there can be something wrong with your car. Resetting the light, as described above, is a troubleshooting tip to see if it is merely a glitch in the ECU or perhaps some modification that tripped it off and needs to be reset.
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From: I live in an ER
I don't think you have messed anything up.
the S2000 ECU is a "Learning ECU"
you should have let it idle for a little bit then drove normally.
ECU Resets are done for tons of reasons.
the S2000 ECU is a "Learning ECU"
you should have let it idle for a little bit then drove normally.
ECU Resets are done for tons of reasons.
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From: Monrovia
The waiting for 15 min after shutdown before disconnecting the battery cable would only apply to MY 06 and newer. So no problem there.
As for resetting the ECU on a pre-MY 06, pulling the backup fuse as pointed out by NVMY4N is the recomended method. However the service manual say's to remove it for 60 seconds.
After the ECU is reset you should perform the Engine Idle Learn Procedure. Basically you turn off all the lights and accessories and let the car warm up until the engine fan comes on. After its warm you let it sit and idle for 5 min not counting any time the engine fan runs during this period. Hope that makes sense.
As already stated the ECU learns over time. Even if the Idle Learn Procedure is performed the idle may try and stumble when coasting to a stop for a while. Don't try and compensate by giving it gas. This may confuse the ECU's attempt to learn. Over time the idle should smooth out.
As for resetting the ECU on a pre-MY 06, pulling the backup fuse as pointed out by NVMY4N is the recomended method. However the service manual say's to remove it for 60 seconds.
After the ECU is reset you should perform the Engine Idle Learn Procedure. Basically you turn off all the lights and accessories and let the car warm up until the engine fan comes on. After its warm you let it sit and idle for 5 min not counting any time the engine fan runs during this period. Hope that makes sense.
As already stated the ECU learns over time. Even if the Idle Learn Procedure is performed the idle may try and stumble when coasting to a stop for a while. Don't try and compensate by giving it gas. This may confuse the ECU's attempt to learn. Over time the idle should smooth out.
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From: The Dragon's lair...
Originally Posted by NVMY4N,Oct 16 2007, 02:02 PM
Originally Posted by s2000news.com c/o Stookfreak
Resetting the ECU/Check Engine Light
Put the fuse back the right way, not upside down otherwise it will not work.
Put the fuse back the right way, not upside down otherwise it will not work.
?
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From: South NJ
Thanks everyone for your input, Im glad the Waiting 15 mins after shutdown only applies to the MY06 and newer 
.
So i take from what ive read, that the rough idle after the Re-set is normal?
i guess i should have let it idle for awhile, before just getting in it right away and driving.
Im just going to re-set it again today, by using the correct Method above.
.So i take from what ive read, that the rough idle after the Re-set is normal?
i guess i should have let it idle for awhile, before just getting in it right away and driving.
Im just going to re-set it again today, by using the correct Method above.
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From: South NJ
Originally Posted by JDS2KNJ,Oct 16 2007, 02:01 PM
Why did you reset your ECU Jay?
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