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ECU reset

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#22 ·
well i have 1500 miles now, that should be enough to warrant a reset.

however the above procedure looks different than what i remember - i remember driving during the boost-holding part?
 
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#23 ·
As long as you can maintain positive boost pressure for greater than 5 seconds, it should work. Doing this without breaking will be a bit tough to do, so I guess you could theoretically brake torque the car while it is moving so you don't end up at an excessive rate of speed. I'd try it is 3rd or 4th, starting just below boost RPM (3 grand or so), then start accelrating while applying brake pressure at the same time. For those worried about burning out the clutch, this could be an alternative method.
 
#24 ·
"so I guess you could theoretically brake torque the car while it is moving so you don't end up at an excessive rate of speed"


I'm intrigued as to why you would prefer to load the clutch than the brakes... I would think that the load on the brakes for 5 seconds on a freeway at full boost would cause much less wear than using the clutch and brakes to hold the car stationary at full boost

But I don't know much about it, so perhaps I'm missing something...
 
#25 ·
bluedog said:
"so I guess you could theoretically brake torque the car while it is moving so you don't end up at an excessive rate of speed"


I'm intrigued as to why you would prefer to load the clutch than the brakes... I would think that the load on the brakes for 5 seconds on a freeway at full boost would cause much less wear than using the clutch and brakes to hold the car stationary at full boost

But I don't know much about it, so perhaps I'm missing something...
Click to expand...
I'm thinking this is getting a bit more complicated that it is. It's simple. Turn car on. Put clutch in. Set E-brake full on. Place in 3rd. Give throttle. Slowly let up on clutch while giving throttle to keep RPMS above 3K/positive boost pressure. Keep clutch slightly out and throttle slightly in for ~ 5 seconds. Done.

There is likely less abuse to the clutch than a normal spirited takeoff. It's over before you know it. Yes, you can also brake torque it while moving, but for me, there is now a safety risk to others when focusing on doing this rather than driving. I'd rather keep it safe and simple right in my own driveway.:thumbup:
 
#27 ·
It is more a "ratio" type increase in HP, so the more your are putting out, the less you will feel it after you reset the ECU. Yes, it still works with stage 1-2 maps, but isn't as noticable when compared to a stock map.

Also..some folks might be forgetting...this happens anytime you reset your ECU eventually anyway...it just takes longer if you let it "learn" on it's own.
 
#29 ·
I just bought an 02 wrx about a month ago. it came with a catback and CAI.

My question is, is it a good idea for me to reset the ECU??:confused: I do not know the history of the car.

If i do reset the ECU, how long will it usually take to learn without doing the 3rd gear trick or breaking?

Thanks for the info! Good write up.:thumbup:
 
#30 · (Edited)
My experience has been that the ECU basically adapts to your driving habits. This has a lot to do with open/closed loop tuning/response which I won't get into right now, but suffice to say, your car "learns" in a non-boost mode, and uses preset set maps once you are into boost.

So, if you drive aggresively after an ECU reset, for the period of time that you drive this way, the car will respond a bit quicker and retain it longer. The intial change would take anywhere from a few days to a few weeks. However, not everyone continuously accelerates hard into boost, every time, every shift, so eventually the ECU will adapt and the car looses some of the edge.

The only time I ever did this was once before a trip to the drag strip, and a few times for non-hp related items associated with maintenance or modifications. I kind of look at it as eventually, it settles back down to it's normal..."all-around" settings where it is good at everything (accel, passing, gas mileage, etc), but no longer has that slightley better kick in the pants feeling the reset gives you.

Also something to consider..the reset lasts about as long as the first set of knock events are recorded. Once that occurs, timing starts getting retarded and the ECU learns that whatever caused the knock to occur is a no-no, and will adjust accordingly. Typically, this will happen on hot days, or if you get a dose of bad gas. Which is why my thoughts have always been that if this is the case, then basically I am sitting on the edge when it comes to ECU tuning parameters every time I reset the ECU. So I ask myself, is this really worth it to me? Not really. Does it really hurt anything? Probably not, but as my daily driver and a father of 4, it just doesn't fit into my overall equation to even go there. For others...shouldn't be an issue at all.

Just so everyone is clear, these are my thoughts and experiences, and certainly should not be taken as gospel, hard-facts. Yours will certainly be different and you should approach how you drive and treat your car accordingly.
 
#31 ·
After my ecu reset, I'm now getting hesitation at 5000rpm every now and then. So much that even my wife noticed it, and she's not too interested in my car behaviour.

After the pause for about 0.5 seconds at 5000rpm, it continues hammering towards the redline as if nothing happened. Quite strange to me...

Has anyone else found this? Is it a common side-effect of the ecu reset?
 
#32 ·
bluedog said:
After my ecu reset, I'm now getting hesitation at 5000rpm every now and then. So much that even my wife noticed it, and she's not too interested in my car behaviour.

After the pause for about 0.5 seconds at 5000rpm, it continues hammering towards the redline as if nothing happened. Quite strange to me...

Has anyone else found this? Is it a common side-effect of the ecu reset?
Click to expand...
do you have an 07 STi?
 
#34 ·
I figured out the strange hesitation type effect at 5000rpm. It's the clutch slipping. At first it seemed like a bit of hesitation, and then now it's much more obvious. The rpms start to rise out of sync with the road speed at about 4000rpm when the boost hits, they go up, then come back down again. Looks expensive :sadwave:
 
#35 · (Edited)
Oops

Ok, so I got my 2004 WRX last fall used with about 50k miles on it. I've since put about 6k on it. I haven't done any modifications myself however I can see that the previous owner has done a few. I know for sure that he installed a typhoon intake system. The only other modification that I know of is I've adjusted the clutch a little (just two turns).

I decided that I would try the ecu reset since I had been driving with regular fuel up until recently and have now switched to 93 octane. I went out to a secluded parking lot and disconnected the negative terminal. Pumped the brakes a few times and then hooked the terminal back up. I started up the car and ensured that it was properly warm. I set the emergency brake and put it in third. I started letting out on the clutch and accelerating. I got to positive boost and was holding when I heard a pop and smoke started billowing out from somewhere underneath the intercooler. I immediately stopped and shut off the engine. Smoke kept coming for a while but eventually cleared up. It smelt kind of like I had set off a bottle rocket or something. After I let it cool down I started it right up and drove it home (gently mind you). I haven't moved it since. Any ideas as to what I could have **cked up?

I should mention that I've never really been into cars much before, the most I had every done was change my oil and brake pads so I'm not completely familiar with all the terminology and definitely don't know what I'm doing.

***Edit***

I should also mention that when I heard the pop and saw the smoke that the rpm's immediately started going down but the boost stayed about the same until I let up on the gas.
 
#36 ·
Directly beneath the intercooler is the transmission, to the passenger side of the intercooler is the turbo, towards the bottom front of the intercooler is the intake manifold and the throttle body. Can you give us a more exact location?

Also, was it black, grey, white, blue-grey smoke? Any sounds on the drive home?
 
#37 ·
The smoke was gray in color. The smoke and smell seems to be coming from somewhere around/beneath the throttle. I had a buddy look at it to help me identify where it was coming from and we started it up and revved it a bit. No more smoke but as soon as you start it the smell comes back very strong. He said the smell smelled electrical to him but we couldn't find anything.

My buddy's hypothesis is that the computer may have not been trained well enough to handle that kind of stress and was operating in an open loop allowing some raw fuel to come back and have a back fire. He's not a mechanic by any means but he definitely knows a lot more than I do. Anyone else think this may be the issue or is there more than likely something else that I should take to get checked out?

This photo isn't of mine but I've used it to try and show you where the smoke and smell came from.
 
#38 ·
Did you stop and check to see if any fluids were on the ground where this happened? Have you been under the car to look in that same area?

There are many reasons why this happened in that area:
1. popped a coolant line and spilled coolant overy your exhaust
2. popped an oil return line from the turbo and spilled oil on the exhaust
3. Roasted your cat which plugged the exhaust then popped a gasket letting exaust come out the front.
4. Clutch/brake master cylinder let loose (doutdbull from the location)
5. Turbo is smoked.
6. A wire/hose is touching the exhaust manifold/tubing.

I can think of a few other reasons too. First, you need to get the car up in the air and closely inspect the engine/tranny. You also need to check the CEL history and see if any issues are showing up in the ECU. If you can't identify the source with inspection/CEL check, try slowly increasing rpms in neutral and while driving to see if you better identify the location. Also have a look at your exahust to see if any smoke is coming from it.

Check these things out and get back with us. Sorry you are having this issue. First I've heard of something like this.
 
#40 ·
@Jimbolion
I hope it goes well :)

Is it necessary to reset ECU the way described here after flashing to a new map using AccessPort?
 
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zax
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