Relay problem.

[Doya]

There has been a weird smell coming from it. I'll open it up tomorrow and check. Thanks for your help, much appreciated

[Doya]

Ok, so I just opened up my ECU (it smelled like burnt plastic) and saw a small burnt spot about the size of a dime. So I guess that means my ECU is bad

[OutToWinPAHC]

Sounds plausible. try a new one.

[Doya]

Yeah, I'm going to see if my cousin will let me borrow his just to test and see if it is the ECU or not. Thanks for all of your help man

[OutToWinPAHC]

Just really make sure nothing externally is shorted which cause the ECU damage to Begin with.

[Doya]

This whole thing first started when I was getting my car pulled to a friends house to have him weld me a downpipe. When like halfway there, that buzzing started. Do you think it could have anything to do with using the brakes when the car isn't started.

[dfddfd2]

This whole thing first started when I was getting my car pulled to a friends house to have him weld me a downpipe. When like halfway there, that buzzing started. Do you think it could have anything to do with using the brakes when the car isn't started.

No, not directly, however there is a wiring issue somewhere causing power or ground to connect someplace it isn't supposed to. I would make sure all non-factory wiring is disconnected before trying another ECU.

Dave

[Doya]

No, not directly, however there is a wiring issue somewhere causing power or ground to connect someplace it isn't supposed to. I would make sure all non-factory wiring is disconnected before trying another ECU.

Dave

Will do.

[OutToWinPAHC]

Not exactly. The older Nissan trans used Darlington pair transistors as well as older FET transistors that do break down and run hot.

I think the problems is external myself, but it could be a simple component breakdown.

[zerepdivad]

Take a picture of it. My friends old hatch he picked up to flip burnt up a trace on the ecu out of nowhere and it was 100% stock. It too was an automatic. i still got the picture somewhere.

[Doya]

I had to borrow my sister's camera to take a pic. It's kind of hard to see. It's in the lower left corner.

[Doya]

Ok, so my cuz won't let me try his ECU because he is afraid it might fry his So I'm just going to have to buy one and wait for it to get here I also noticed that the wires on my Intake air temperature sensor were cut all the way through. Could that make a difference.

[OutToWinPAHC]

It could short out something for sure. Fix it before you try another ECU and go over the wires again just to be sure.

[Doya]

It could short out something for sure. Fix it before you try another ECU and go over the wires again just to be sure.

I don't think I will be able to fix that because the wires are completely pulled out of the sensor and there is nothing for me to attach the new wire to.

[OutToWinPAHC]

Well make sure they are taped and separated for now. Hit a local u pull it and check other Nissan for that temp sensor. If they have it clip the harness so you can splice it in to yours.

Oh and the burns looks to ge near the power supply capacitor, control resistor and PS diode. Probably for the +5 volt circuits. My guess would be an external short that caused that.

[Doya]

Oh and the burns looks to ge near the power supply capacitor, control resistor and PS diode. Probably for the +5 volt circuits. My guess would be an external short that caused that.

Is there anything in specific I should check for an external short.

[OutToWinPAHC]

My guess it was what you may have already found cut in half. But damaged sensors, burnt or cut harnesses would be my guess.

[OutToWinPAHC]

take the board out and hold it to the light and see what pin that burnt trace goes out on.

[Doya]

My guess it was what you may have already found cut in half. But damaged sensors, burnt or cut harnesses would be my guess.

I hope that it is that sensor. I'm going to go over all of my sensors and harness again just to make sure.

I'll check the ECU out tomorrow and trace what pin it goes to.

[Doya]

I couldn't figure out what pin it went to but I removed all of the wire loom and inspected all of my wiring. I found out that the Black/White wire going to my MAFS plug was fried. The previous owner had extended the wires to relocate the MAFS to the passenger side and it turns out that there were two bare spots on the black wire and the black/white wire.

Anyways, it melted the wire all the way to were the first injector is. I'm going to cut it and put new wire on it from there. I'm just glad that it didn't mess up any of the other wiring.

[dfddfd2]

I couldn't figure out what pin it went to but I removed all of the wire loom and inspected all of my wiring. I found out that the Black/White wire going to my MAFS plug was fried. The previous owner had extended the wires to relocate the MAFS to the passenger side and it turns out that there were two bare spots on the black wire and the black/white wire.

Anyways, it melted the wire all the way to were the first injector is. I'm going to cut it and put new wire on it from there. I'm just glad that it didn't mess up any of the other wiring.

The blk/wht wire is +12V from the ECCS relay. The blk (signal ground) and wht (0-5V signal) wires go back to the ECU and should be a shielded pair with the shield grounded at one end only.

Dave

[Doya]

Yeah, I traced the wiring back and found out that the black and white shielded wires go to the ECU and the black/white wire goes to the ECCS relay, like you said. It only burned the black/white wire though, I guess because the other ones were shielded. I should get my new ECU today so I"m going to finish up the wiring and see what happens

[OutToWinPAHC]

good luck

[BRIGHTBOZEMAN]

I HAE HAD THE SAME PROBLEM TWICE - THE PROBLEM IS THIS - THERE IS A 7.5AMP FUSE UNDER THE HOOD THAT HAS BLOWN OUT -SITTING RIGHT NEXT YOUR HORN RELAY (EGI 7.5A FUSE) HAS TO BE REPLACED

REGARDS, BRIGHT BOZEMAN

[Doya]

So yesterday I just got it running (it took a long time because of a mix up when I was buying my ECU) but my dash lights and my radio and all that other stuff still won't come on.

[94_240sx]

So yesterday I just got it running (it took a long time because of a mix up when I was buying my ECU) but my dash lights and my radio and all that other stuff still won't come on.

Sounds like your TCU is fried. It's a white box right below the fuse box under driver's side kick panel. Of course, check the fuses first.

[Doya]

I've already checked all the fuses twice. Oh well, at least it running

[sx moneypit]

Glad to hear you finally got car running!

[Doya]

Glad to hear you finally got car running!

Thanks I was going to let you know but I couldn't find that other thread.