Problems after ECU Reset

[ButtonMasher]

Hi guys,

So I reset my ECU by disconnecting the battery so that it can go into the learning process again. Was curious to see if performance will change after break in. So when I got into the car to start it up, the car wouldn't start. I pushed the key all the way but the only thing that happened was that the electronics turned on. However it started like normal on the next try. Why did it not start the first time?

Also I let the engine idle for 10 minutes as recommended and as it was idling, the car was vibrating like a massage chair. You could feel it through the chassis.

10 minutes go by and I take it for a quick drive. Now I noticed that the rpm drop was back when I came to a stop.

Is all this normal after a ecu reset? Will it go away eventually?

[zc06_kisstherain]

why did you reset your ECU? what problem you had before resetting ECU?

i wouldnt worry about it did not start on first time since it starts fine now.
RPM drops back? did you have this issue?

[continuecrushing]

Don't worry about not starting the first time. Automatic or manual? Maybe you didnt step on the clutch all the way the first time?

and 10 minutes of idling is 9 minutes too long.

Unless you get the latest flash/ECU update at the dealership(usually they will say your car doesnt need it) or have a tune(like the OFT), the dip is gonna be there at idle.

[ButtonMasher]

I've had the rpm drop when for a while but it comes and goes. I reset the ecu because I saw a thread talking about making the car re learn your driving style after the break in period. Figured it couldn't hurt to try.

[continuecrushing]

Originally Posted by ButtonMasher

I've had the rpm drop when for a while but it comes and goes. I reset the ecu because I saw a thread talking about making the car re learn your driving style after the break in period. Figured it couldn't hurt to try.

Yeah, RPM drop is pretty normal/common. If you pick up a handheld tuner like the openflash tablet, the idle rpm will be much more stable...not to mention better drivablity.

Don't think resetting the computer after break in does anything, car was slow before break in and its slow after. But resetting it doesn't hurt anything, other than making the gas pedal really suck for a couple days.

[strat61caster]

Originally Posted by zc06_kisstherain

why did you reset your ECU? what problem you had before resetting ECU?

i wouldnt worry about it did not start on first time since it starts fine now.
RPM drops back? did you have this issue?

The drive by wire throttle needs to know it's full range of motion when it's first set up.

For me, my throttle has all it's response in the first 40% of travel, I could modulate the throttle at any point through the last 60% and the passenger wouldn't notice anything at any rpm and am contemplating doing what the OP did in an attempt to get a more linear throttle response.

http://www.ft86club.com/forums/showthread.php?p=1317901

[extrashaky]

Originally Posted by ButtonMasher

So when I got into the car to start it up, the car wouldn't start. I pushed the key all the way but the only thing that happened was that the electronics turned on. However it started like normal on the next try. Why did it not start the first time?

This is apparently normal for Subarus. When you disconnect and reconnect the battery, the computer goes through some kind of system check before allowing the car to start. You tried to start the car before it finished its test to confirm that everything was still there after the power loss.

[ButtonMasher]

So is there anything to explain the vibrations? It was pretty strong

[continuecrushing]

it was probably because the car was barely idling enough to stay on...so it felt rough.

Was your a/c on? That could have made it worse.

[Yamajee]

Happens to me all the time, don't worry about it. I've reset my ECU for god knows how many times. Hell, I even drive it a bit after resetting and whenever I'm gonna press on the clutch as I approach a traffic light the car stalls, the vibrations are normal, the "heavy" gas pedal feel is also normal, give it a few days and all of this will be gone.

[steve99]

Originally Posted by ButtonMasher

Hi guys,

So I reset my ECU by disconnecting the battery so that it can go into the learning process again. Was curious to see if performance will change after break in. So when I got into the car to start it up, the car wouldn't start. I pushed the key all the way but the only thing that happened was that the electronics turned on. However it started like normal on the next try. Why did it not start the first time?

Also I let the engine idle for 10 minutes as recommended and as it was idling, the car was vibrating like a massage chair. You could feel it through the chassis.

10 minutes go by and I take it for a quick drive. Now I noticed that the rpm drop was back when I came to a stop.

Is all this normal after a ecu reset? Will it go away eventually?

Guys,

their is no point in resetting your ECU to "make it learn" its learning all the time. All it will do is reset counters and DTC/CEL codes and reset the fuel and ignition learned parameters to default values.

see here

http://www.ft86club.com/forums/showthread.php?t=68328

If you want to update your ROM to latest calibration and dealer won't do it

http://www.ft86club.com/forums/showthread.php?t=62332

[FRSpappa]

Just reset my ECU today and what a dog! Currently have an intermittent idle dip the car didn't have until I installed a new intake. Glad this gets better...


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[Yamajee]

I had to disconnect my battery for my aftermarket steering wheel and seat install, I had to reset it for a lot of CEL's, I don't believe in the ECU "learning" whatever has been modded to the car as @steve99 said that it goes back to its default value on the map that is in the ECU, if you want it to "learn" then go for EcuTEK, I'm sure that'll turn out great for mods.

[steve99]

Originally Posted by Yamajee

I had to disconnect my battery for my aftermarket steering wheel and seat install, I had to reset it for a lot of CEL's, I don't believe in the ECU "learning" whatever has been modded to the car as @steve99 said that it goes back to its default value on the map that is in the ECU, if you want it to "learn" then go for EcuTEK, I'm sure that'll turn out great for mods.

The ecu even on the stock tune learns fueling and timing information, its always learning it never stops but it only learns within certian limits.

A tune will adjust the base maps in the ecu for generally for better power and torque but often at the expense of economy or emmisions and to better take advantage of any modifications. A tune will also adjust cam timings which are not learned ecu just folows the mapped settings.
A tuned ecu map will still learn fuel and timing setting like an untuned map however the tuner may increase or decrease the amount of learning and adjust a lot of other parameters that are not learned or adjusted on the fly.

The learning allows the ecu to run as close as it can to the mapped settings by accounting for differences in fuel altitude temperature ect, but their are limits to these adjustments