ecu no power please help.

Discuss topics related to the CA18DE and CA18DET series engines.
beans33
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When the key is in the ON position, the lights on the ecu are not lit up. Ive basically took out the whole engine harness and connected everything back together, but still no luck. Ive checked all the fuses that I know of and all of them still are good. My cd player, turbo timer, and accessoriers all still work. I just noticed it one day when my safc didnt come on. This just happend out of nowhere. Any kind of help would be appreciated, as I am totally lost on what to do now.


beans33
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please.. its still just sitting out there....

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biosehnsucht
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are all the relevant wires from the dash harnes connected to the ECU harness still? have you checked for power at the various pins on hte ECU?

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lifelicksballs
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wait isnt off but when you press on the gas the red light comes on or something?

pulsar gtr
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On the dash harness, only connect the wires with the same colors, and the rest that don't match just don't connect them.

Could you tell us which wires have you connected on the CA harness to the the Ka body harness behind the battery, you might have missed a wire or crossed one.

Also, have you check for power at the ecu to make sure you are getting power on the proper pins. If you do have power on all the pins that should have 12v, double check continuity from the battery ground to all the ground wires on the ECU.

If you don't know which wires are the 12v and ground on the ecu, let us know and I will try to look them up and post them.

Good luck,RafiPULSAR GTR

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capowered240
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on the dash wiring, do you have the orange wire hooked up? That is the wire that gives power to your ecu when you have the ignition to the on position.

beans33
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Yea I checked the orange wire and its good. I remember reading a post about it not to long that said its important. Well my ecu came on but it was blinking the lights. But now my fuel pump wont come on, checked fuel pump relay wire behind the battery and its getting power then i checked it at the ecu and its good also. I hard wired it straight to the battery and it came on. Is there anything else that would not make it come on ? Ill still post tommorow the wires in the engine bay, because the ecu lights will come on randomly, unless the ecu is on and the lights are off, maybe its in some kinda mode. Im not sure. I checked all fuses and they are good. Where is the fuel pump relay, is it the egi in the fuse box ? thanks
Modified by beans33 at 8:56 PM 10/25/2005

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biosehnsucht
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is it blinking very very fast blinkblinkblinkblinkblink or is it slow w/ pauses

if its fast something is definately wrong because whats happening is the ECU is stuck rebooting..

when I forgot to expand my ROM to fill all the (unused) banks on my 512k chip once I had this problem, also if you put it in backwards you can too (but that leads to frying things as opposed to just rebooting)..

check ALL the fuses/relays EVERYWHERE in thecar.

EGI sounds right for the fuel pump relay.. but I'm too lazy to go look. Also, there is a fuse for the fuel pump in the same box.

the random lights sounds like definate either fried ECU or bad power connections..

beans33
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well i tried to see if it would come on this morning but it never did. The wires by the battery go like this. Black/pink - black/pinkred/black - red/blackred - redgreen/orange - green/orangeblack/red and blue/red - black/whiteblack/yellow - black/yellowblack - black

the left over wires on the ka harness are: red/blueyellow/greengreen/yellowpink brownyellow/blue

im goin to go check all the fuses and relays to make sure all good. thanks

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float_6969
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Use this guide from the Heavy Throttle site...

Engine Harness & Electrical Connections

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Our engines come with a complete, uncut harness and lower engine harness that includes the transmission sensor plugs and the starter, alternator and oil pressure sender wiring. Common places to have the harness incorrectly cut are where it runs into the firewall to the ECU, and right at the back of the valve cover, keeping the injector and plug harness, but usually missing the ECU, MAFS, igniter chip and their wires. There are 2 plugs on the end of the KA harness and 3 plugs on the SR harness that run up behind the stock battery location. Although the plugs do initially snap together, the wires do not line up and you have to cut the plugs off and connect the wires using the table below. Cut the 2 main KA plugs off the KA harness and splice them onto the SR harness.

SR Harness Wire Color Use KA Harness Wire Color Black / Pink stripe Fuel Pump Relay Black / Pink stripe Green / Orange stripe Transmission Neutral Sensor Green / Orange stripe Red / Black stripe ECU Relay Red / Black stripe Green / Yellow stripe AC Relay Green / Yellow stripe Red ECU Backup Power Red Black / Red & Blue / Red (Note: connect 2 wires to 1) Main Ignition Power Black / Red stripe Black / White stripe ECU Power Black / White stripe Blue / Green stripe AC Relay Blue / Green stripe Black / Yellow stripe Idle Air Control Valve Power Black / Yellow stripe Brown (to O2 sensor) O2 Sensor Power Any 12v switched source

The MAFS and power steering sensor wires need to make it over to the front driver's side of the engine compartment, use the MAFS and PS wires from the KA harness to extend these wires. The AC compressor wire from the KA engine bay harness should be used NOT the SR harness AC wire (even though it fits). The starter and alternator plugs to the fuse box are all the same and plug right in. There are several unused and leftover harness plugs, anything not mentioned here does not need to be connected.

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ECU & Dash wiring

The colors on the wires that run from the ECU up into the dash matched up perfectly on both the SR ECU harness and the KA dash harness:

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Wire Color Use Yellow / Red stripe Tachometer signal Yellow / Green stripe Speedometer signal Orange Ignition start Black (may be more than one ground) Ground Blue / Green stripe AC signal Blue / Black stripe Water temp signal

The rest of the wires are for the CONSULT diagnostic device. It is not necessary to connect any other wires than those listed above to get the SR to run properly.

Connect the remaining wires if you plan to use the onboard diagnostic CONSULT connector.

The Apexi turbo timer is connected to the O2 sensor wire at the ECU to provide auto countdown functions. The Apexi AVC-R is also attached to the ECU harness for tachometer signal, speed signal, and throttle position. Apexi products come with a very good ECU pinout diagram that is extremely useful.

Remove the brackets from the SR ECU to make it easier to mount.

beans33
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yea thats what i did and all of its connected right but my ecu and fuel pump still are not coming on. ( ecu the lights arent coming on and i cant hear the fuel pump come on at all its walbro, makes the whining noise) I checked all the fuses in the engine bay and they seem to be good. Can anyone tell me if there are any relays that might have something to do with this that im not finding. Or if there are any grounds. This will be about my 4th time cover my whole harness and ecu. I still cant find what the problem is. Would the cas or dropping resistor have anything to do with this ? thanks

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biosehnsucht
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none of the sensors should cause this - unless perhaps something wrong with them fried your ECU.

if its not the wiring, fuses, or relays, its your ECU.

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capowered240
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Did you check the ecu and fuel pump relays? To see if it is the relays or not, change out the two relays with the same color relays.

1. Fuel PumpWhat you could do is take a Digital multimeter with the ignition to the on position, go back to where the fuel pump is and put the positive probe on the hot wire and the ground probe to ground. If it shows that you are getting power back there then the fuel pump is bad since you don't here that whining sound. If it is not getting power back to the fuel pump, then its in the wiring somewhere.

2. EcuBasically the same thing. Take a DMM, with the ignition to the on position, put the positive probe where the orange wire is and the ground probe to ground. If it shows that you are getting power to the orange wire with the ignition to the on position, you might have a bad ecu.

This is what I would do if I had this problem. Try the changing of the relays first. If still no luck then try what I had said above (1,2).

pulsar gtr
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HI Beans33,

I took a look at your wiring and I believe I found some discrepencies.

Here is what you have and what you should have.

Your black/red and blue/red - black/white is wrong and should be as follow

black/red & blue/red connects to black/red NOT BLACK/WHITE

ALSO YOUR green/yellow should hook up to green/yellow, DON'T REALLY HAVE TO HOOK IT UP AS IT GOES TO THE A/C RELAY. IT WILL NOT MAKE ANY DIFFERENCEas well as your brown wire should hook up to another brown wire WHICH ALSO SHOULDN'T MAKE A DIFFERENCE.BUT YOU NEED TO FIX THE FIRST ONE AS IT SUPPLIES POWER TO THE ECU.

on the dash side you should only have these wires hooked up.

BLACKBLUE/BLACKBLUE/GREENORANGEYELLOW/GREENYELLOW/RED

GOOD LUCK,RafiPULSAR GTR
Modified by pulsar gtr at 9:27 PM 10/26/2005

beans33
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Car: 1993 ca18det 240sx

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Thanks pulsar, You were exactly right. The ecu and fuel pump are both now coming on. I appreciate it thanks again.

pulsar gtr
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Hi Beans33,

I am very happy and glade that I can help a fellow member.Congrats and cheers.

PULSAR GTRRafi

fre0005
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Car: Silvia s13 ca18det

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pulsar gtr wrote:HI Beans33,

I took a look at your wiring and I believe I found some discrepencies.

Here is what you have and what you should have.

Your black/red and blue/red - black/white is wrong and should be as follow

black/red & blue/red connects to black/red NOT BLACK/WHITE

ALSO YOUR green/yellow should hook up to green/yellow, DON'T REALLY HAVE TO HOOK IT UP AS IT GOES TO THE A/C RELAY. IT WILL NOT MAKE ANY DIFFERENCEas well as your brown wire should hook up to another brown wire WHICH ALSO SHOULDN'T MAKE A DIFFERENCE.BUT YOU NEED TO FIX THE FIRST ONE AS IT SUPPLIES POWER TO THE ECU.

on the dash side you should only have these wires hooked up.

BLACKBLUE/BLACKBLUE/GREENORANGEYELLOW/GREENYELLOW/RED

GOOD LUCK,RafiPULSAR GTR
Modified by pulsar gtr at 9:27 PM 10/26/2005
Sorry old thread just came across it.. Which wires are these?? As I'm not getting power to the ecu, I recently put a ca18det into a s13 shell and can only get the fuel pump going by jumping the terminals 1/5 in the relay but have no spark or power to ecu
I don't have the cluster connected is this a problem and am I supposed to plug other wires in the the ecu engine harness from the body loom ??

boost_boy
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It doesn't take much novice screw-up to burn the ecu and it already sounds like you have some shady stuff going on there. Did you have a complete and unmolested CA18det jdm Harness? Or is this a wiring harness out of someone else's project? Answering these question will help me and the forum help you with your dilemma. Way to revive an old thread and it actually shows you did do some searching...lol


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