blown ecu ground

[accidentaldsmer]

Ok thanks to an earlier thread I had earlier i've come to the conclusion that my ecu ground is blown... I opened it up and sure enough there doesn't seem to be anything grounding it. I even checked continuity and it doesn't beep when touching the bare copper on it. I've looked up a couple picture and now know which one is pin 92 but I can't seem to find where i can ground it to, I also oppened up my 95 eprom ecu and there also doesn't seem to be a ground on it so i'm kinda confused on that I bought it as a working one but never installed it. I also have a 98 ecu which is the original one from the car but i'm hessitant to put it back in especially since I can't even get the thing open, so if anyone has any hints on how to open a 98 ecu the one with the black box i'd really appreciate it.

here are some pictures of my ecu and where I think the ground should be around

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here is a whole pic

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and finaly does this look like a leaky cap???

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thanks

 

[jdxnc]

I've experienced a blown ground. It burnt the trace on the lower right hand corner of your full view image.

Here's mine that blew, I successfully jumped the burnt spot with a wire and the ecu worked fine after. This was caused by a melted o2 sensor wire, the heater wire shorted to the ground. So you better find out what caused it as well before trying to fix it.

You can see the burnt spot right below the orange things:

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[accidentaldsmer]

Nice finally a ecu thats similar to mine
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Only I'm still not 100% where to soder I see the burnt part on yours but no trace on mine. Do I go all the way to c1 from pin 92?

or just on the spot right on top of d2 which seems to be connected to a tiny black box..

 

[snowborder714]

blownsensorground [ECMTuning - wiki]

 

[accidentaldsmer]

blownsensorground [ECMTuning - wiki]

Thanks, only problem with this picture that it's slightly different from my ecu.
I just switched an older ecu in there that I don't remember what was wrong with but still showing me a -40 reading on the temp sensor.

Is the white strip what i'm trying to soder over or is that the stock ground??

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[93_tsi_fwd]

Also check the back side. get a flashlight and look very carefully. I blew my sensor grounds and it was a very little line on the trace.

 

[steve]

I do not see a blown sensor ground in your pictures.

Try measuring the engine coolant temp sensor resistance at the ecu harness. Pin 82 is the ECT sensor and pin 92 is sensor ground. It should read about 2.1k ohms at 66*F dropping as the temp increases to about 260 ohms at 176*F. Then measure again at the sensor.

 

[accidentaldsmer]

thanks steve I was seriously starting to go in that direction but only after I did some scrapping on my ecu, just a tad on the white strip but enough to expose bare copper, do you think that'll mess with anything? I'll check ohms as you suggested and also another quick question for you I have a newer style ecu from a 98 the one with the plastic black box, do you know the trick to opening them? I've tried the obvious but it doesnt seem to budge and the bracket just bends...

 

[steve]

I pry them up enough to slip a penny or a dime in next to the catches and then once all four are released you can pop the board out.

 

[habitatguy187]

Go Steve!