ECU fried?

mk3supra978

New Member
Nov 9, 2010
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MASS
hello everyone i think my ecu is fried anyway i could test this ? has anyone ever had a fried ecu before ?car will not start at all turn the key on and the only lights i get is the door is open light other than that nothing please help ? another question anybody know where the ecu is located in a 1990 supra turbo ? and could i use a 1989 supra turbo ecu to test to see if thats the problem or does it have to be from a 1990 supra ?
 

hvyman

Dang Dude! No Way Man.
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Apr 17, 2007
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Highly doubt its the ecu. Its very rare for a 7m ecu to go bad without user error.

Check to make sure the little blue wire is connected to the battery positive.

Also check all your fuses.
 

mk3supra978

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Nov 9, 2010
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checked everything possible that why its the ecu.fuses all good wires on connected to grounds n stuff so im guessin its the ecu any other suggestions ?
 

jrot

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Apr 11, 2010
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knob noster, MO
i have a extra ecu if you need it man...its an 89T cali ecu so if your not in cali car it will give you a egr code but its cool....lemme know...your welcome to it as its just sitting here....use it if it works and if not send it back or what ever....
 

boostcraver

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Mar 13, 2010
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We need more info if you want intelligent answers and more than blind guesses. Are you hearing any clicking from the starter relay under the dash? Turn the headlights on and try to start it. Do the headlights dim, or do they stay constant? What is your battery voltage? Is the battery DEFINITELY good? From what you have said so far, I would suggest you check out these threads as the symptom (not starting) is addressed here: http://www.supramania.com/forums/sh...-Starter-Relay-Mod)&highlight=start+everytime
and here: http://www.supramania.com/forums/sh...or-the-first-time-and-starter-won-t-kick-on-(
Hope this helps.
 

hvyman

Dang Dude! No Way Man.
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Apr 17, 2007
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What about head lights and interior lights?

7m ecu's dont just go bad.

Is the ecu plugged in all the way along with the other connectors down there.
 

mk3supra978

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Nov 9, 2010
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no headlights and the only interior lights that work are the door is open sign other than that no inside lights
 

jrot

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Apr 11, 2010
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knob noster, MO
your ecu i dont think would have anything to do with your interior lights....sounds like youve lost some sort of connection somewhere....maybe your main power or ground...sounds like your whole fuse box has messed up....and are you sure you dont have some sort of issue with the alarm/imobilization?
 

hvyman

Dang Dude! No Way Man.
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Apr 17, 2007
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Ya the ecu does not control lights other than the check engine light.

You have a power problem. Take out the multi meter and start at the battery.
 

jrot

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Apr 11, 2010
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knob noster, MO
yes absolutely. taking a car to a shop for unknown electrical issues they can take as long as they want and just through a ton of parts you probly dont even need at it.....be best to spent the time at it your self....i really feel like its gonna be an annoyingly simple solution.....check all your grounds really well.....or do like the gentleman said earlye and get out your multi meter and start at the battery and work your way through....
 

shaeff

Kurt is FTMFW x2!!!!
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Mar 30, 2005
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Didn't read much of this, in a hurry. Check the fusible link. Grab it and wriggle it around. It should be pliable. Check continuity through it/resistance. Without that in proper order, you won't get power in many areas.

Did you by chance hook the battery up backwards?


Edit: just realized you have a '90, so it might have a large fuse instead of an oldschool fusible link. Check it anyway.
 

MKIIINA

Destroyer of Turbos
Mar 30, 2005
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did your alarm go off? the stock alarm acts as a kill switch if tripped and will do what you describe. might want to check into that....
 

mk3supra978

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Nov 9, 2010
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MASS
i got it to crank but still wont start got my headlight back all lights workin now except for the dash lights inside the car it seems like no fuel is going thru anybody know what can it be ?