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going through ecus

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92gsxbafaro

10+ Year Contributor
256
24
May 20, 2011
Spokane, Washington
so not to long ago my car would not start so i go to pull out the ecu and find that my ecu is blown along with the isc so i replaced both thinking that that would fix it but when i tried to start it again it still wouldnt so i looked at the ecu again and one of the caps blew or leaked.. my question is what is causing this to happen?
 
my question is what is causing this to happen?
A short circuit.

Generic questions can only garner generic answers. Post some pics of the ECUs. Give us more info.

Usually duplicate ECU failures are from an ECU driver not seeing enough impedance. If you had a problem with the ISC wiring, that could explain it. There's no way for me to be more specific without getting more specific info from you.
 
okay i uploaded a couple pics in my profile the one with ic105 blown was the first ecu and the other one just has the cap looking burnt.. there are only two pics i just uploaded them a whole bunch on accident and cant figure out how to take them off ha
 
I think at this point your best bet would be to contact a professional...May I suggest ECMLink? They do great work, have a fast turnaround, and come highly recommended. I've used their repair services myself, and would only send my dsm ecu's to them.
 
I think at this point your best bet would be to contact a professional...May I suggest ECMLink? They do great work, have a fast turnaround, and come highly recommended. I've used their repair services myself, and would only send my dsm ecu's to them.

this ecu isnt broke yet i am worried about turning my car on and blowing it again i dont know what is causing them to blow im not that good with electrical im just wondering what i should be looking for that could cause this
 
this ecu isnt broke yet i am worried about turning my car on and blowing it again i dont know what is causing them to blow im not that good with electrical im just wondering what i should be looking for that could cause this

luv2rallye is one of our few and far between electrical wizards, I always pay special attention when he posts.
I'll only offer this in light of his post:

Make sure the ISC is good and make sure there are no shorts in the wiring to the ISC before you do anything else. In particular check the wiring to ISC coils B1 and B2. Both of those failures you gave pictures of could be related to a problem with the ISC or it's wiring.

there are only two pics i just uploaded them a whole bunch on accident and cant figure out how to take them off

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luv2rallye is one of our few and far between electrical wizards, I always pay special attention when he posts.
I'll only offer this in light of his post:

Make sure the ISC is good and make sure there are no shorts in the wiring to the ISC before you do anything else. In particular check the wiring to ISC coils B1 and B2. Both of those failures you gave pictures of could be related to a problem with the ISC or it's wiring.

okay i know the coils in it are good i just bought it and tested it. i just dont know how to check the wiring what exactly am i supposed to do, like what wires too test?

i turned the key on and tested the voltage in the plug and i only got voltage in 2 and 5. am i supposed to have voltage in 4 of them because on the ecu there are 4 pins for that right?
 

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i turned the key on and tested the voltage in the plug and i only got voltage in 2 and 5. am i supposed to have voltage in 4 of them because on the ecu there are 4 pins for that right?

No, the two center pins on that connector have power and the other outside 4 go the the ECU where it connects them to ground in a specific pattern to cause the ISC coils to flow current and move the pintle in or out. Until the ISC is plugged into the connector there won't be a voltage present on the others. (because a voltage on one end of a coil of wire will show up on the other end.)
 
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No, the to center pins on that connector have power and the other outside 4 go the the ECU where it connects them to ground in a specific pattern to cause the ISC coils the flow current and move the pintle in or out. Until the ISC is plugged into the connector there won't be a voltage present on the others.

so would you say that the wiring for the isc is good at this point if i have voltage to that?
 
so would you say that the wiring for the isc is good at this point if i have voltage to that?

Isn't that kind of like asking if your health is perfect because you can see that your breathing.

There are six wires, you need to check that each reaches from the connector to where it ends (like the ECU) and doesn't connect to ground or one of the other wires along the way. So far you know the two power lines have power and that the other 4 don't. The chances are good that the other 4 are ok and that the ISC wiring isn't the source of any ECU damage, but It's not usually the wiring (except when it's wet) but the ISC that blows the ECU drivers. The wiring keeps the ISC from working correctly.

Find the end of the connectors for the Boost Control Solenoid (BCS), Fuel Pressure Solenoid (FPS), Purge Solenoid (PCS), EGR Solenoid and make sure they aren't shorted, that the harness is plugged into them, or that it's covered up so it can't get wet if the solenoid isn't there.

Then it should be pretty safe to try the new ECU.
 
Isn't that kind of like asking if your health is perfect because you can see that your breathing.

There are six wires, you need to check that each reaches from the connector to where it ends (like the ECU) and doesn't connect to ground or one of the other wires along the way. So far you know the two power lines have power and that the other 4 don't. The chances are good that the other 4 are ok and that the ISC wiring isn't the source of any ECU damage, but It's not usually the wiring (except when it's wet) but the ISC that blows the ECU drivers. The wiring keeps the ISC from working correctly.

Find the end of the connectors for the Boost Control Solenoid (BCS), Fuel Pressure Solenoid (FPS), Purge Solenoid (PCS), EGR Solenoid and make sure they aren't shorted, that the harness is plugged into them, or that it's covered up so it can't get wet if the solenoid isn't there.

Then it should be pretty safe to try the new ECU.

okay thank you very much!
 
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