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Miguel Silva

Relay control by THUNDER ECU problem

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Hi to all,

 

I'm having some trouble with the relay controlled by the THUNDER ECU on my NISSAN 300ZX, they just don't pass enough voltage when they are switched on, battery is at 12.5v and the voltage output after the relays is +-10.5v.

The ECU powers up but the injectors don't have enough juice to click at 10v and the ignition also doesn't power up to use a timing light.

To my understanding relays just have 2 states ON or OFF.

I had to do a modification to the original wiring harness as injector had battery power all the time and created a feedback on the THUNDER, so I installed a relay to the injector circuit as can be seen on the attached images red circuit inside the pink area (pink area is based on the Thunder Hold Power Low Side Wiring that I altered to suit the stock harness).

When I use this same circuit on a NISTUNE ECU this modification is completely transparent and the voltage out of the relays is the same as battery give or take 0.02V and car runs perfectly, so the relays are not to blame.

If I manually bypass the relays the THUNDER ECU sees 12.0V and I can perform injector tests on the software.

So can the THUNDER pull a better ground to make the relays close better?

I'm using a patch loom made from the A and B Loom Part # 5LB and # 0LA.

Should I try a thicker wire for the "main relay+" and "main relay-" ?

 

See attached images and thanks in advance for any help.

Miguel Silva

 

wiring_modificado.thumb.jpg.3941edcbbf33.

Initial_wiring.thumb.jpg.481ec0cf60dda5a

20161228_160227.thumb.jpg.fc330a9bc23ebf

Edited by Miguel Silva

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Mine had low voltage like this when the ecu hold feature was not setup correctly in the software. You will find that the main realy will not close causing the voltage drop. You will get voltage both side from back feed but you need to confirm the relay closes

Edited by Ducie54
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What happens if you manually ground pin 16?

Have you confirmed you have ground to the battery on pin 107 

PIN 16, I'l try it, and see if it beavers differently.

 

Well PINS 107, 108 and 116 all share the same ground on the stock harness, and is used by the PTU and Ignition coils, and ends on body and engine grounds.

And again on the NISTUNE ECU (it's the stock ECU with a real time programmable ROM) the ignition works fine.

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Mine had low voltage like this when the ecu hold feature was not setup correctly in the software. You will find that the main realy will not close causing the voltage drop. You will get voltage both side from back feed but you need to confirm the relay closes

But if the main relay isn't closing why is the ECU powering up on key on and powering down on key off?

Can it be from back feed of the control solenoids that's getting power direct from ignition switch without a relay, tricking the ECU to have power?

The hold power doesn't have many options:

Digital input - (high or low) I have it on high

Main relay driver - (off, test on, ecu hold power) I have it on ecu hold power

ECU hold power - (time, kill until stalled-yes/no) I have it on 10s and Yes

 

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Ecu is powering up from ignition switch input

Change main relay to test on and see if the voltage increases

I think I already tried it and no change, but just to be certain I'll do it again in case the test I've done was on a different context!

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What happens if you manually ground pin 16?

Have you confirmed you have ground to the battery on pin 107 

If I manually ground PIN 16 the relays close and I get battery voltage minus 0.5V  on all +14V inputs, it's a bit of a drop but it's okayish!!

If I disconnect PIN 16 "Plug C PIN 1(Main Relay +)" and PIN 107 "Plug C PIN 8(Main Relay -)" and join them together the relays close and the same as above so PIN 107 has ground.

PIN 45 "Plug C PIN 2(Ign Sw)" is active when key ON, see image below, and is configured as (active high).

Screen.thumb.jpg.143374280da06996fb21ffe

When all this PINS are connected back to the ECU, I've tried All 3 options, OFF, Test (ON) and ECU Hold Power and the relays don't change state, they are always open.

I'm using Firmware 5.6.4.3240 and the PCLink G4+ EN-JP V5.6.4.3229 software.

I've also attached .pclr that I'm using.

G4+ 300ZX Thunder very basic.pclr

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Settings look the same as mine, Can you try PIN 107 on a separate ground to 108 &116. 

I'll make a new wire and connect it to a new and good chassis ground and to "Plug C - PIN 8(Main Relay -)" and test it.

Edited by Miguel Silva

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Settings look the same as mine, Can you try PIN 107 on a separate ground to 108 &116. 

I did the new wire and connect it to a new and good chassis ground and to "Plug C - PIN 8(Main Relay -)" and, more of the same, relays don't close.

Next I used PIN 16 and plug it to IGN 8 "Plug B - PIN 10" and configured it as an ECU Hold Power output, PIN 45 plug it to DI 7 "Plug B - PIN 30" and configured it as an Ignition Switch, burned it to the ECU, cycled the key ON and OFF and it didn't close the relays also.

Next configured IGN 8 output to "test on" "polarity low" and as expected the relay closed juts like when grounding PIN 16.

I then configured IGN 8 to "GP Output" "Condition 1 ONLY" "DI Value 7 = ON" and cycled the state of DI 7 to ON and OFF and the relay opened and closed as expected. Burned it to the ECU and cycled the Ignition key a couple of times and the relay always come alive with key ON.

So I wold say wiring and relays aren't to blame.

Every time I try to use the Hold Power option, I can't make it work.

I'm probably not configuring something right and need help troubleshooting this.

It can work like this, but i lose the Hold Power option.

I've attached the .pclr file from the last configuration with the GP Output.

G4+ 300ZX Thunder IN OUT config GP on main relay.pclr

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To me the settings look right. Its like the ECU is not grounding PIN 16 correctly Can you try it like the below pic. Just to confirm you are using a normally open relay with resistor? 

If you send me an email at nigel.duce@bigpond.com ill send you a full diagram on how i wired mine up. I did mine differently. 

ECU_hold.thumb.png.643d5d7e225a90a12857b

 

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I noticed you have DI-7 configured as Ignition Switch ... the Thunder G4+ has a dedicated Ignition Switch out put.

Could the DI-7 config. be causing a problem ?

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I noticed you have DI-7 configured as Ignition Switch ... the Thunder G4+ has a dedicated Ignition Switch out put.

Could the DI-7 config. be causing a problem ?

No, this was just configured to test if the ECU sent the command to ground (in this case PIN 16 and plug it to IGN 8 "Plug B - PIN 10" but as I posted above it didn't work configured to ECU Hold Power but it does work as  "GP Output" "Condition 1 ONLY" "DI Value 7 = ON" and cycled the state of DI 7 to ON and OFF and the relay opened and closed as expected. Burned it to the ECU and cycled the Ignition key a couple of times and the relay always come alive with key ON.

But this isn't a Hold Power function as I don't have the option to hold the relay closed after key off.

But on "G4+ 300ZX Thunder very basic.pclr" file the DI 7 is blank and it doesn't work. And that is the base for the post.

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Did u get my email?

Yes, I did but I'm out for a couple of days with no accesses to the car, I didn't try yet.

What you have is ROKET not a car :) you've got gaziillion things going on there.

One more thing I'm going to try is to remove the fuse that feeds power to the sensor and see the reaction, this way the only power coming in is on the "main relay+" and  the "Ign Sw", if this finally makes it work I just have to add a relay to that part of the circuit.

About the ".3 of a volt lower than AUX 9/10 and AUX 17-20 even tho the the voltage in the ECU was the same on all 3 wires" mine does that too, Some thing that bugged me but I was going to confirm what rely goes in the PINS and what is red by the ECU.

 

Again thanks allot for the help.

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