Resolved 2G No power to the ECU

[KeelesKustome]

Hey i need help

My ECU is not receiving any power to pin 12 or 25, thus causing my car to not wana try to crank and the fuel pump not coming on.
The relay in the dash behind the radio has been changed 3 times and it never makes any clicking noises. This relay also does not have a constant 12v going to it like I think it should even when the key is off.

What's weird is when I probe the fuel pump wire at the ECU with my test light while having the key on acc, the pump will run until I let the probe off.

I have messed with the neutral safety switch with no luck.
On my ECU pinout it says the wire should be black, this is not the case, it is black with a red stripe.

I would like to try and bypass the N switch at the transmission, as it is an automatic 2g, but I can not figure out the wiring schematics on how to do so, and I am unsure if this would allow power to enter my ECU even if I did.

I checked and bypassed the 20amp, 30 amp, and the 100amp fuses under the hood one at a time to make sure this was not my problem, it did not help.
Every now and then I'll hear some clicking coming from where the neutral safety switch is located.

I also changed the ignition switch with no luck.

I also locked and unlocked the car with the key to make sure it wasn't some safety feature,

I also ran a wire from the fuse panel with a constant 12v to the MFI relay where it says 30 amps, as this is suppose to stay charged and it doesn't, with my hard wire it does but has not fixed the problem and the relay still does not click or allow power to the ECU.

I am considering the neutral safety switch, how do you get rid of this on an automatic that is staying automatic?

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I connected the neutral safety wires, red with black stripe big, to the black big wire, nothing changed.

I tried grounding the last mentioned wire, it already had ground and i added one, nothing changed.

I ran from the 30 amp fuse power to the #12 and 25 pin the ECU starts up and shows the CEL light for 5 secs, so that's a sign the ECU is good I do believe. Problem being the relay still isn't triggering the starter and the fuel pump, why?

Also side note, now when the ECU is working, so does my keychain to lock and unlock the doors, I checked to make sure it wasn't the security system again and it is not.

Please shoot me some more ideas to do, as I have swapped every other MFI plug in the car where this one is and it isn't changing a thing, and i know they are good because I have tested them in other spots. The MFI plug seems to not be making it's ground properly, where should i look for this at?

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Okay so here's what I have done, the MFI relay: I added a ground to the side that wasn't getting it for some reason, this allows the starter to now crank over.

Although the CEL light isn't coming on because it's still not getting power, so i add the 30 amp fuse direct path power wire to one of the terminals, i think 25, now the fuel pump kicks on and it turns over and the CEL light comes on for 5 seconds.

I am here by myself so checking for spark is hard, i manage, and i have none.
I can only assume that the relay is messing that up too. I think what the heck is going on with this?

I have swapped this relay numerous times and still nothing, and how come i am not getting fire even bypassing it?



some info I might try that I found.

Here is the short version of what it says to check for the relay.

Section 4-3, Fuel Injection Control Relay Check. (just the relay)
This tests the MPI side of the MPI relay
step 32 - Remove EFI relay
step 33 - Connect battery positive (+) to terminal 10 and battery negative (-) to terminal 8
This should activate the one side of the relay causing it to connect pin 10 to pin 4 and 5
step 34 - Connect voltmeter negative probe to the battery negative terminal, Connect voltmeter positive probe to terminal 4 and then to terminal 5, There should be 12volts at each terminal.
if you do this before step 22 you'll see pin 4 and 5 don't have 12v before hand and do after

This tests the fuel pump side of the MPI relay
step 35 - Connect battery positive (+) to terminal 9 and battery negative (-) to terminal 6
step 36 - Check for continuity between terminals 2 and 3, there should be continuity, next remove the ground lead from terminal 6 and check again, there should be no continuity.
step 37 - Connect battery positive (+) to terminal 3 and battery negative (-) to terminal 7
step 38 - Check for voltage between terminal 2 and the battery ground, there should be 12v
step 39 - If the test results are incorrect, replace relay with new part.

According to this my relay passed, but maybe not.

What this doesn't test is that MPI relay is functioning in the car. For that you need to check that you have 12v at the connector for pin 10 all the time, turn on the ignition switch and verify you have 12v at pins 4 and 5 when the ignition switch is in the run or start position.
If the the relay checked out but you done see 12v at 4 and 5 then you need to look at the ECU and the signals going to it. )

 

[sniver]

Pic looks opposite yes.

Your not deleting any wires.

You combine two into one. (red)+(black/w/red)---->(red)

And split one into two. (blk/wht)--->(blk/wht)&(blk/wht)

You will end up with 8 wires when your done splitting and merging.


Gsxtasy, your double pics hurt my brain. good info, but I feel skull raped making ends of it, despite how strait forward it is. Looks good on paper.

Its a relay ....how hard can it be...it says open sesame, and the sh!t opens.
Boss man(+) says open her up to the guard(-). guard opens gate and lets traffic through....we've had the idea of a relay since the idea of gates.

 

[GSXTasy005]

yeah, sorry about the double-pics, I'm too lazy to log into photobucket and upload, then link. and I wanted to add comments to accompany the pics. just ignore the "attachments" section

 

[KeelesKustome]

okay I'm frustrated so I'll make this simple.
I just went and rewired it correctly, cranked it and still nothing, no power going to the fuel pump.

the white wire with red stripe is getting 12v
the red wire with black stripe is getting 12v


the black wire with white is getting like .075v

I realized my ecu light didn't come on......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

So much has been done i can't remember if it came on last night, My memory is becoming jumbeled.

okay......here we go again.

I need to check ignition power supply? Does the black wire with white stripe come from the ignition switch or the ecu?
Would this keep the ecu light from comming on?

 

[GSXTasy005]

The blk/wht wire comes from the ignition switch. It should only see 12V if the key is on. Make sure both red/blk wires see 12V at all times.

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[KeelesKustome]

the red wires do have 12v all the time.

the black with white ,sees below a volt with ignition off or on.

 

[GSXTasy005]

interesting...... can you unplug the ignition harness, then redo the exact same test you did to get those results. i want to eliminate the wire between your ignition and those relays. while you have it unplugged, can you also check continuity between the ignition plug and the relay plug on that wire?

 

[KeelesKustome]

i can but not untill monday

it's got me confused as why thats not seeing the switched power, and my ecu light isn't coming on.

 

[GSXTasy005]

the ECU is not powering on, AND the black/white wires are not getting power correctly. can you test for voltage at pin 82 on your ECU? both with ignition on and off. it's something to do with the ignition somewhere, I can feel it in my gut

 

[KeelesKustome]

same here man, Keeping my head straight is key at this verry moment, If i can hold it together I may go by the shop tonight, otherwise it will have to wait untill tomorrow.
I know i'm on the home stretch because everything is working like it should except for this 1 single issue, and that is a vass improvement.

 

[sniver]

FYI if that damn turbo timer harness is the issue in any way, Me and GSXtasy are flying over to beat you with 2x4's. Just wanted you to be aware.

I think this is going to be the solution we've been looking for, hopefully its a open wire somewhere thats findable.

 

[GSXTasy005]

... I'm too lazy to externally host pics! what makes you think I'm going to take time out of my day to fly anywhere?

but seriously. I expect an apology if it's that turbo timer harness.


sounds like it's close to starting tho. with this being the only issue now.

 

[KeelesKustome]

i have a question.

the black wires with white stripe, going to the fuel pump relay,

does it go to this spot on the ignition harness? the plug on the right.

and does that lead to the ignitor harness plug that sits on the im on the left here.?

the ignitor sensor is not bolted to anything, i was told it didn't have to be by a fellow member, is that correct?

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[sniver]

The black/white wire comes from the ignition switch. Is that the switch harness?

As for those pics, I'm not that good, I can't ID connectors sitting on your couch . One on the left looks like the power transistor plug for the coils... How about you zone me in a bit. Is this plug/s located in the interior, engine bay..


What is a ignitor sensor? I may have one on my BBQ.... ??

 

[KeelesKustome]

I can identify every single sensor wire on this car, even when i don't know how all the wires are ran.

the one on the right extends out and has another plug that plugs into the ignition switch, it is much smaller and white. it doesn't have any black wires.This one, plugs into where the alarm goes. under the dash on the drivers side

the one on the left is the coil transistor.

 

[GSXTasy005]

Damnit.... now you're going to make me unwrap my harness to find out. The one on the left goes to the ignition transistor, it's usually bolted to the intake manifold. It does NOT have to be bolted down for the car to run. I hope that answers one question. As for the other plug... is that one that goes behind the radio? Because that's what it looks like to me. I'll have to trace that one and get back to you.

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[sniver]

Did you ever check the ignition plug for power,or are you looking for opens before verifying that there is supposed to be power in the wire to start with ?

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[GSXTasy005]

Sniver kinda said what I wanted to. Have you tested the power wire before the ignigion switch, the one that's supposed to be "hot at all times"???

The one thing that has remained constan through this whole thing, is that harness. You haven't tried swapping that yet, have you?

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[KeelesKustome]

seriously..........

I am starting to realize ya'll aren't comprehending what i am even giving you.

I told you i would check the ignition power wire monday.

in the meantime before i went back to the shop i am trying to also locate where this black wire with white stripe goes to get it's switched power.
I specificly told you the plug on the right goes underneath the driver side dash and plugs into the fuse block right near the security harness, yet your saying it looks like it's coming from behind the radio......

but yes not having to bolt the ignitor is what i was also after

 

[sniver]

¿No hablo ingles?

Lol I said I don't know where one was, and guessed on the other correctly.

I don't care when you go to the shop, that's your buisness. I am just asking for the feedback loop you horribly SUCK and posting. . I get your sick of it, I've been there. Your almost there so relax a bit, once you figure out this wire, chances are it'll be allllllll betttterrr.



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[KeelesKustome]

i hooked up the new reray and it fired right up.
a few hrs later i reinstalled everything and got my laptop and now the fuel pump isn't getting switched power again.... and it won't start.

all wires from the ignition are getting 12v except the black with red stripe and it gets it when i crank the car.

pin 82 get 0 unless switched on then 12v.

pin 80 backup power has 12v

but pin 12 and 25 are only recieving 0.75 v with key on or off.

so no ecu light this time.. what the heck did i do, i mean it ran.............. now it won't

on the relay all the power wires have power and the oposite site is all correct except the black with blue for the fuel pump isn't getting anything with key on or off...
please reply asap whuile i am here at the shop.

 

[sniver]

I'm eating, I'm not sure which one that is off hand. Isn't that suppposed to be a trigger wire?

I thought power was black w/ red & black w/white. (Trying to think, not positve.

So your not getting power where? To the ecu to kick the mpi and fuel on, or...?

Check fuses, you ought to be doing backflips, while crying.

If it ran and died, either a fuse blew, or you have a semi open wire. Shake some sh!t and see what that gets you. If you make if run, poke about and see if you can kill it.

Ill finish eating and check back.

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[KeelesKustome]

no, it ran and didn't die, i cut it off, because of the fuel not being tuned.

the mpi relay is getting 12 volts to everything except the fuel pump trigger wire.

but the ecu power wires aren't getting 12v and all the fuses were checked and are good.

all ignition wires are giving the 12volts as well.

what controls the 2 ecu power wires? i think this is my issue. the are red with black stripes.................. those aren't the same 2 that go to the relay are they?

 

[sniver]

You have backup power to the ecu, it lies dormant until it gets power to activate via the ignition switch, then it commands the relays on.

The the ecu connects pins 8 and 38 to ground. This in turn allows power to flow from the mpi fuse, and the ignition switch through ecu to ground, thus activating the relays. Then and only then the power flows from the mpi fuse, and ignition switch into pins 12 & 25 therby powering up the ecu, turning the cel on for 5 seconds and the whole nine yards.

If the ecu ground is bad, it won't work. If the mpi or the igniton has no power it won't work. If there is a break in the four wires to the ecu from the relays no go...

Check post.... like 5 ,for better detail.

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[KeelesKustome]

they all have power. so why isn't it working.

 

[95TSi_AWD_717]

Check for a broken wire in the harness if you haven't checked it yet. Sniver Knows I had a similar problem and to find there was a broken wire.