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Why does my 2004 honda civic keep blowing the ecu.
Car: Honda, Civic, 2004, 1.7 - Back to Fix-It - Honda Civic Repair Manuals
Q.Why does my 2004 honda civic keep blowing the ecu.
I already checked/done: It all started after I changed thetiming belt, water pump, and tensioner (all bought from Honda) then the coustomer left the lights on all day when she was in school, got someone to boost her drove home and the next day the car had no power, the tach ,the PRNDD1 would not work. Have you ever heard of this before and if so what could the problem be By the way I am a lisenced mechanic and hve never seen this before.
More Info required does it keep blowing the fuse for the ecu or does it actually cooks the ecu..
Addition it actual fries the computer this is my second computer.
More Info required did this just start happening out of the blue..
Addition Yes as I siad it just started happening after I changed the timing belt, water pump and tensioner then the coustomer left the lights on all day and killed the battery.
Then she got a boost and drove it home, it was alright untill the next day when she started to go to work, then no power the rpm gauge and the prndd2d1 quit working an dthat is when I checked with my snap-on solus pro and found no communication with ecu.
My freind that works @ kanata honda checked it and said that the computer was cooked. I hope this will help
More Info required to cover the basics did you check all the fuses. And could you clarify what you mean b the prndl does not work. Do you mean it will not let you out of park or it will light up or what..
Addition the prndd1 means the lights on the dash for park, reverse, neutral, drive and drive one do not light up, must be on the same curcuit but they lit up before and yes I checked all the fuses also my freind from the honda dearlership said that there is a known problem of the wiring rubbing through by a plastic tie at the right hand side bottom of the fire wall so I checked all the wiring and seems to be alright, also I checked and monitored the alternator output to see if there was a spike, but none was detected in the hour I was running it but unable to monitor it when I took it for a test drive, only went about one mile and it went back to same as after the first computer fried. That is all I can think of at this time
Answer the lights being out islikely a bulb that is out, how are you determining the ecm is fried. What is the car doing that makes you think the ecm is fried. You would have to have a short somewhere in the harness that is shorting to ground to cook the ecm over and over.
Does your code reader not talk to the computer or what is the car doing that makes you think the ecm is fried.
Addition The answer is incomplete. Not that it is wrong but instead the pro is not understanding what I have already said. I think that the computer is fried because when I hooked up the new one it runs like a brand new car, so what else could it be.
Addition If the computer is not fried then why when I hook up another computer does the car run like it was brand new. The bulb is not burnt out for when I hook up the new computer the bulb is lit again. And the scanner does talk to the computer once the new ecm is installed. Please don't talk down to me as if I was a office worker that does not know a thing about a car.
More Info required uh ok I was merely trying to see what made you think the ecm was fried not talking down to anyone.
There has to be a short somewhere in the circuit for the prndl and the ecm I can give you a schematic of this circuit but to find the short you are going to need to do some heavy meter testing to find where the harness is shorted causing your ecm to fry. When this happens do you get any check engine light or anything else that stops working in the car.
Does the car still run ok just the light on the cluster do not work need to try and narrow the schematic search down to a specific area if possible.
Addition Yes the car losses most of it's power but still runs and you can still drive it but it is very slow like you have to put it in low gear to get started and then to drive and you can still get to hiway speed but chuggs alot, I haven't noticed anything else that does not work except p. R.n. D.d1 , rpm gauge and the check engine light comes on. I drove it back to my shop about 2 miles. I think thats all.
More Info required doe sthe chec engine light come on and flash at all
Addition no, but I forgot to mention that the immobilzer light does flash, sorry hope this is not a big thing, but it does flash the immobilizer key. The check engine comes on but doesn't flash as of this time.
Answer it seems to me as though you have a pretty good short to ground somewhere in the harness.
These are next to impossible to find via the internet as you are going to need to trace the harness looking for a shorted wire. You could also have a short in the gauge cluster that is causing the issue.
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