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Is my ECU bad??

Posted: Thu Jul 09, 2009 2:25 am
by gijonas
God damn this thing just wont give me a break.

So after trying to reset my ECU tonight due to an ongoing hiccup hesitation problem that has not gone away,i cant seem to reset it.The first time i reset it all went well just like it was supposed to,now not so much.after connecting plugs under dash and doing the pedal dance i go for a drive and wait for the CEL to blink.Well now when the light decides to blink(after a minute or so) it just keeps repeting code # 42 (idle switch)?? I seem to remember before that when reseting it would just blink once or twice. Not only this but when i connect just the black plugs to read the codes i dont even get 42 i get a 22.On top of this the codes are staying in the memory and not resetting???? WTF is going on here?

All of this and now the car constantly fall s into severe lean spots while driving regardless of situations, anywhere from 17:1 and maxing out the LC-1 at 22:1

Posted: Thu Jul 09, 2009 3:06 am
by 91legacyawdturbo
Sounds like a bad idle air control valve to me. The Subaru ecu will not fully reset until the original problem(s) are fixed it will continue to bring up the code.

Posted: Thu Jul 09, 2009 3:18 am
by gijonas
I am replacing the TPS tonight.I am just worried that the code does not show up when checking codes and only when trying to reset the ecu...Oh well'i'll know more later.

Posted: Thu Jul 09, 2009 3:23 am
by SLODRIVE
Have you tried adjusting the idle switch/TPS as per the FSM? I had the same code and similar symptoms, and that took care of it.

Posted: Thu Jul 09, 2009 6:49 am
by RJ93SS
ecu's can be tricky. on my dad's recently we would drive around with the engine light on and it would spit a 22, then in drive check mode we would get a 22 and after 45 minutes of driving we would get the nuetral start switch code. that code would not show up on the regular code check.

then at the mechanic he also pulled another code that never showed up for us.

the hesitation is likely caused from the 22 code your getting.

Posted: Thu Jul 09, 2009 3:28 pm
by gijonas
What a ride this was :roll:

I got it back in order last night.I had forgotten to say that i was trying to reset the ECU not only due to the issues i was having but also because i had replaced the knock sensor and wanted to start clean.Unfortunately i not only broke a wire on my o2 sensor while removing my uppie earlier(also had to change the uppipe), but at the same time my TPS had somehow gone out of range.By this i mean it must have been bumped somehow causing the idle switch to be open at closed throttle position.After running around with my multimeter and reading the FSM i loosened the screws on the TPS moved it just slightly and got it back to proper position.
SLODRIVE Posted: Thu Jul 09, 2009 2:23 am Post subject:

--------------------------------------------------------------------------------

Have you tried adjusting the idle switch/TPS as per the FSM? I had the same code and similar symptoms, and that took care of it.



:D

Anyways after fixing the o2 wire,adjusting the TPS and then actually resetting the ECU i now have an engine thats running better after 10 miles of learning than it was after 1000 miles :roll: ,I cant wait to see how it runs after a 1000 miles from now :)

BTW: these cars are easy to work on but they can be a source of much confusion i find.

Posted: Thu Jul 09, 2009 11:22 pm
by gijonas
OMFG this thing is going to kill me!! everytime i think i have resolved an issue it just pops back with what seems like a different cause.I really need to stop jumping the gun and thinking my car is running ok.The hesitating bucking crap is still going on and to boot i have a really noticable surging issue going on during acceleration.Feels excellent for half a second then lags for half a second repeat repeat,and i can actually kind of feel this a bit while cruising as well.I have no idea what there is left for me to check here and this starting to really get to me.Despite all the crappy running that is going on i am now not getting any codes from the ecu,so i dont know what its problem is.I feel that without logging i have no chance at figuring this out,unfortunately im not sure i would know what i was looking at even if i could log it.

Posted: Fri Jul 10, 2009 1:17 am
by ScottyS
Don't get too discouraged! I also have noticed a slight background pulsing occasionally with my car too, but as of now I am writing it off until I get the major tuning issues sorted. It sounds like this is the same problem as yours, and I'd love to figure it out myself.

Heavy pulsing under boost can occur with the first version of the Revtronix chip (if you are using the factory BCS), this next version that is shipping should have that rectified.

Posted: Fri Jul 10, 2009 5:04 am
by log1call
Jigonas, that sounds like old fashioned over-advanced ignition timing.

Do you know what your advance curves are like?

Posted: Fri Jul 10, 2009 7:21 pm
by gijonas
^ no idea.