Ok so heres what I have, a wrecked 04 Impreza Sport and a blown motor in a 2004 Impreza TS. The sport is a 5sp and the TS is an auto. I am taking the motor out of the Sport and putting it into the TS but I am pretty sure the ECU in the TS is also shot (my CEL wont illuminate).

My thought is to put the ECU in the sport to see if it works, will that work?

My second question is if the ECU is dead, can I put the sport's ecu into the ts car? If I can, are there any mods I am going to have to make or reprogram the it?

ECU's very rarely fail, i wouldn't assume the ECU is bad until you do some appropriate testing.

Can it be tested without any special tools? How would I go about testing it or would putting it into my running subaru work? Sorry, I do not have a lot of experience with ECU's

in some cars you can swap auto and manual ECU's, i've done it with older subarus, but i doubt one this new. you could always try it, they're easy enough to swap out.

 

your ECU is not bad. it's almost silly to think it was running fine....motor blew...and then the ECU is bad....how would it fail after the motor blew if it's got no motor to run? the ECU was running fine...right up until the motor blew up...then the ECU failed the second it blew. or it failed in *all that use* the car got after the motor blew up? i don't know that i can overestimate how unlikely this all sounds. i'd get on with your motor swap then trouble shoot whatever comes your way after that.

 

if your CEL is not coming on then check the light bulb or fuses first.

you can PM/email me if you want to mail me your ECU to test in my 2003 auto.

Edited December 13, 201015 yr by grossgary

Thanks! The only reason we wanted to test the ECU is because we bought the car with a blown motor so we have no idea what happened. My boyfriend went to drain the oil out last night and he drained about 3qts of gasoline out of the engine???? Not too sure what is up with this motor but he is going to hook it into the wrecked car just to see and check all the fuses and so on. Hopefully its just the motor and not a new ECU because then we may be swapping the transmission too if it makes a difference with the ECU.

Thanks for your help!