FD Seeker

I have found a decently priced ECU and OMP - which encourages me to think I might be able to fix this myself without going bankrupt. I believe I can easily replace the ECU, but I don't want to do that until I've identified if there is some other problem with the car.

I'm told that the ECU deals with low power signals that shouldn't ever cause a burning type short. Therefore, it makes sense to me that 'frying' something in the ECU is being caused by some short (or something) outside of the ECU.

Honestly, I don't think I'm capable of diagnosing the exterior problem. Does anyone have suggestions on testing for a short somewhere? Otherwise, I'm goin to have to pay $300 for TriPoint to just look at the car - plus towing both way$.

FD Seeker

I removed and opened up the computer to see what I could see. Sure enough, there is a computer chip (?) that is obviously fried - and possibly two other small diodes (?) next to it. Unfortunately, all this does is confirm that something in the computer fried. I still don't know what (if anything) in the car triggered this.

Can these specific components can be replaced?

Rx7aholic

iTrader: (22)

It's very hard to change the black long chip the other small one {red } should be very easy. I recommend u change the whole entire ecu, get another used to buy, Also u defnitely have a serious short somewhere from the ecu to the engine harness. I sugguest u double check every wire harness and get a fluke meter and a shop wiring manual u can save your self alot of money.good luck man, I feel your pain.

cr133r

If I came across a problem like this working on someones car... I'd immediately suspect a wiring harness issue. Find the pins that drive the OMP on the ECU harness...

Check to see if any of the pins are either shorted to ground or shorted to +12v. Obviously you should disconnect the OMP while doing this. If nothing turns up, connect the OMP and see what kind of resistance you get across the pins to it. Maybe the OMP shorted out.

I'm not at all familiar with the FD, so I can't get too specific, but these are the things I'd look for FIRST...

My bet would be some wire is shorts to +12v which would most certainly cause the burning you see.

You could possibly trace the burned parts back to a pin on the connector with a DVM... That way you could probably narrow down the bad wire a lot quicker.

FD Seeker

cr133r:
You're right on the money - that's exactly what my next steps are. Thanks for the input

RussellTT94

i have one.......make an offer

FD Seeker

I did some testing today, with an electrictronics savvy brother-in-law. So, I can't personally support some statements I'm making below with methodology.

It looks like I'd have to remove a lot of stuff to get to the harness that connects to the OMP - so for lack of time and courage, I didn't.

Using the FSM I have identified the four pins on the ECU that go to the OMP - and they do appear to lead to the burned component on my board. So, we checked the corresponding pins on the harness that connects to the ECU. I believe we ruled out any of those wires being shorted to the ground or positive. We also got 'expected' resistance results between them based on what they supposedly connect to within the OMP.

While I have not been able to complete the most thorough wiring examintion necessary, I'm CONSIDERING the possibility that the component on the ECU just went bad. The one way I can figure to test this theory is to plug in a new ECU and see what happens. My theory here is that a new (used) ECU, costs less than the diagnosis at Tripoint (and towing).

Am I crazy?

spooledUP7

My mistake

FD Seeker

Well... Ari at Rotary Performance seems to think that the component on the board would not fail as mine has without some cause. Without the benefit of actually inspecting my car, he seems to think that the OMP is the culprit. He says it's possible that the short in the OMP may not present itself until the car is up to temp (or some other conditional reason).

Now I need help getting to my OMP - but I've created a post specifically for that since the search yielded nothing.

hapa

Seeker, I would bet my money that you have a short in your wiring harness. I have never heard of something shorting out in a stock ecu. Have you looked at your engine wire harness? The plastic on mine is all cooked and falling apart. I have already re-soldered several connections to sensors. Start at the oil metering pump, and work your way up and back. A 10 year old plastic wire harness in an oven (which we call an FD engine bay), dies quickly. If your harness is fine, then check the pump (buy I doubt this is the case). If you do need a stock oil metering pump, I know someone in socal that has one in excellent shape.

eric