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Forum namePerformance/Engine
Topic subjectHow to determine bad ECU?
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=81912
81912, How to determine bad ECU?
Posted by coppereclipse95, Oct-19-04 05:51 AM
Is there any way to determine the condition of an ECU? I've been having strange problems with my car and I started to believe my ECU is bad.

Reason: The only time my car starts is when my check engine light comes on. The only time the OBD scanner read codes is when the engine light is on. My car does nothing(doesn't start) when the engine light doesn't come on. Like my fuel pump doesn't prime, etc. OBD scanner doesn't even notice it's plugged when the engine light isn't on.

^^^above made me belive that the ECU isn't working right. Any info will help! TIA
81913, RE: How to determine bad ECU?
Posted by CrazyEclipse, Oct-19-04 05:56 AM
See if you can borrow a friend's ECU to hookup. That's how I found out mine was bad. I am a MTX, and I used a ATX, speedo didnt work, but it still ran better than the original MTX.

How I fried the ECU.... I didnt.... paying other people to do soldering isnt always a good thing. x(
81914, RE: How to determine bad ECU?
Posted by coppereclipse95, Oct-19-04 06:13 AM
Originally posted by CrazyEclipse
See if you can borrow a friend's ECU to hookup. That's how I found out mine was bad. I am a MTX, and I used a ATX, speedo didnt work, but it still ran better than the original MTX. How I fried the ECU.... I didnt.... paying other people to do soldering isnt always a good thing. x(


While you were using your bad ecu, did it run crappy? What kind of problems did you have with the bad ECU?
81916, RE: How to determine bad ECU?
Posted by thedawg, Oct-19-04 06:22 AM
The 95 ECU's have more problems than the other years. I don't know exactly what the problem is, but symptoms usually involve the fuel pump not priming or the car shutting off randomly.

Try a known good ECU, fastest way.

I'm selling one (95 MTX) for $180 shipped.
81951, RE: How to determine bad ECU?
Posted by 95greenhrcgs, Oct-19-04 05:27 PM
When the ECU on my car went out, the car would die randomly ( even when driving down the interstate at 80mph ). Also, it was hard to start. Finally I couldnt even get the Check Engine light to come on and couldnt do the keydance to check codes. At that point, I knew that the ECU was dead.


82008, RE: How to determine bad ECU?
Posted by coppereclipse95, Oct-20-04 04:44 PM
Well, I had a friend with a 95 Avenger ATX...we hooked it up and my car started. Eventhough it was shitty, but it started. I plugged to my computer...nothing. So, I guess my ECU is dead. I need to look for an ECU now. thedawg, I may need you to hook me up with one!

ONE MORE THING: This may sound weired...but personally, I'm not a big fan of buying computer related used. Especially since if it's a used 95 ECU...around 9 years old... I just want you guy's opinion on this. Is it smarter for me to spend more money and buy a brand new ECU? or save money and buy a used one. I don't have a lot of money, but I don't mind spending some if it's worth it. If new, would it be smarter to buy one from chrysler? or mitsubishi? or anywhere that sells new 95 ecu.
now I wish I had a 97...
82014, RE: How to determine bad ECU?
Posted by 95greenhrcgs, Oct-20-04 05:23 PM
Well what I did was break down an dbuy one from my local Mitsu dealer. They tested all the wires to make sure that one of them was not shorting out or fying the ECU. Then they replaced it with a new ECU with a 1 year warranty. It cost me around $580 with diagnostic, parts and labor.

I think you should just buy one from a reputable seller here in the forums, especially if they can offer you a good price. Also, ( especially if its much cheaper ) if you buy one from here and it fails, then you are still not out $580. You never know, if you buy one from here, it may work just fine, and you save some money.

Good luck man
82025, RE: How to determine bad ECU?
Posted by MCubed45, Oct-20-04 06:58 PM
ya satan will rape you on the price for the ECU. you can find a lot from people on here or from the junkyard or whatever.

my ecu used to shutoff randomly while the car was driving. it's kinda weird to stall while ripping down the freeway. it's no big deal as long as it restarts though. finally one time it just died and never woke up again. it sucked. but i got a replacement used one off here for cheap and haven't had problems since.