Nissan GA15DE ECU Wiring Help

[star2]

Ok, for the most people who have swapped GA15De and wondering why it is dropping RPM while turning power steering, switching on the headlights, Switching On Blower Fan, and Car not stable at idle rpm.

Here is something for you.

Usually when the uncut wiring comes with a GA15De, it has two separate grips, one holds 18 wires and one holds 5 wires. The 18 wires one is for multiple accessories relating to cabin or other functions (which i will explain later) and the five wire one is mainly the power grip, supplying +12V to most of the things.

Now, in that 5 wire grip, there is a brown wire, which directly goes to the IACV-AAC valve. I have explained about the location of the valve and its wiring in the very first post with pictures, so you can consult from there.

Now, you just have to cut that wire from that grip if in case its not already cut (brown wire) after checking the continuity between that brown wire located in the five wire grip and the one end connected at the IAC-Valve Grip itself, and you have to supply it with +12V from "ON" i.e. ignition point. Here I am attaching the reference diagram and circuit.

Now what it is and what its function:

This system automatically controls engine idle speed to a specified level. Idle speed is controlled through fine adjustment of the amount of air which bypasses the throttle valve via IACV-AAC valve. The IACV-AAC valve repeats ON/OFF operation according to the signal sent from the ECM. The camshaft position sensor detects the actual engine speed and sends a signal to the ECM. The ECM then controls the ON/OFF time of the IACV-AAC valve so that engine speed coincides with the target value memorized in ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by taking into consideration various engine conditions, such as during warm up, deceleration, and engine load (air conditioner, power steering and cooling fan operation).

The IACV-AAC valve is moved by ON/OFF pulses from the ECM. The longer the ON pulse, the greater the amount of air that will flow through the valve. The more air that flows through the valve, the higher the idle speed.

[badog]

Thnaks for the information, will wait for the other ecu load wire pinouts:)

[star2]

Ok Posting today, a very very important diagram that i was able to pry out from my computer's hard drive.

For those, who do not know, here is how GA15DE ECU gets power supply.

Please take time to investigate the diagram with patience.

For the reference wires, you can look at the Page 1 pinout given in two diagrams.

[star2]

Here is a simple diagram of the Self Shut-Off ECCS Relay. Those who unfortunately did not get the ECCS relay with their wiring, can get a 4-point Nissan Relay and can wire it up like this.

The ECU pinout I have given on the first page under two diagrams, please check.

[Xulfiqar]

@star, WOW you have become quite a pro in this.

[star2]

@star, WOW you have become quite a pro in this.

lol, kidding Xulfiqar bhai

People ask me by phone, so i thought of posting it here. It may be of help to many others.

and for that "pro", i count you as my ancestors now, lol. hats off to ya.

[Xulfiqar]

you will be quite amused to know that I have seen some nissan sunnys in Pakistan with hacked up ECCS kill wiring. Electrician bhai just hot wired the ECU from the key directly and had very neatly hidden the wires.

At that point in time I planned to do some sinister things to said electrician.

[star2]

its really the time we stop wasting our hard-earned money and time to these illiterate electricians' hands. I was the victim of same, hot wired ECU, responsible for strange behaviors of Engine, filling up your inbox all the time, but yes, only you have to come forward and do it yourself full stop. It is not an easy task, not everybody involves in it, but its well worth it.

Now i don't get panic to death when my car's light suddenly stops working or my radiator fan's relay gets water in it and stops working...... I just get it right on my own thanks to people like you ....

[Xulfiqar]

its really the time we stop wasting our hard-earned money and time to these illiterate electricians' hands. I was the victim of same, hot wired ECU, responsible for strange behaviors of Engine, filling up your inbox all the time, but yes, only you have to come forward and do it yourself full stop. It is not an easy task, not everybody involves in it, but its well worth it.

Now i don't get panic to death when my car's light suddenly stops working or my radiator fan's relay gets water in it and stops working...... I just get it right on my own thanks to people like you ....

Its good that you got the sense of it, but your point of "wasting time and money" is not very accepted in Pakistan, I have dealt with customers, and believe me people in Pakistan have no sense and start comparing apples to bananas.

e.g. Honda civic rolls in with shorted IAT sensor fault (IAT sensor bad), I quote him the cost of a replacement Honda sensor and a used sensor and 15 minutes labor, throw in a free car shampoo and wash. - NOPES, the customer says its too expensive and starts to tell me how he had another of his car repaired in Rs 100/- by the galli ka electrician who wired the check light to the battery light.

I never tried to win over such customers because they are a waste of time. This was not limited to a certain class of society but I met people from every "class" like this. They maybe trying to just get free diagnosis, which I started to charge for later on.

On a similar note, I can bet good money that you tell people not to undertake a swap on the trust of electrician or mechanic only.

[star2]

very true Xulfiqar bhai...... u r absolutely right.

[badog]

Keep it coming star2. Another day for me to check my wirings.

[badog]

please help me idwntify these not connected wires from my ecm? pins 2, 9, 7, 14, 15, 23, 24, 32., 35, 44 and 45. i have not finished checking the other wires connected, there are wires that double tap on one ecm pin out. will be checking these too. thanks again.

[badog]

hey star2, got lucky while resting:) check this out ga15de FSM, download the n15 pulsar:
Original JDM manuals VE\VET NISSAN - SR20 Forum

[star2]

that's a great find bro you got it alright

[badog]

Good day star2, have some questions:

1. pin 35. i have a a/t ecm, do I have to ground pin 35? Park Neutral position switch/inhibitor switch (the car starts normally)
2. pin 43. I don't have power steering. manual says I need to supply 5V if not turned. what will I do?
3. pin 33. I don't have a rear defogger. Can I directly connect the h/l switch without the diode?
4. pin 32. I don't know where to get this signal. Is this important?
5. pin 45 and 41. I still have the stock controller of my blower and a/c. Do I have to connect them to the ecm? also relay pins 9, 10, 11 was still in stock wiring.

Alot of questions arise once more:)

[star2]

1. pin 35. i have a a/t ecm, do I have to ground pin 35? Park Neutral position switch/inhibitor switch (the car starts normally)
   According to the diagram, there will be two wires coming out of the inhibitor switch, which is located near the gear i think (go under the car and inspect), one of them will be a negative, leave that, and connect the other one with this pin 35 wire.

2. pin 43. I don't have power steering. manual says I need to supply 5V if not turned. what will I do?
   Leave it un-attended, do not connect it anywhere.

3. pin 33. I don't have a rear defogger. Can I directly connect the h/l switch without the diode?
   No I do not think so, diode is necessary, you only have to give signal one-way.

4. pin 32. I don't know where to get this signal. Is this important?
   Determine what meter type you have..... If you have electronic meter, i.e. its getting speedometer signal from gear, then you can attach pin 32 to that wire at meter portal.

5. pin 45 and 41. I still have the stock controller of my blower and a/c. Do I have to connect them to the ecm? also relay pins 9, 10, 11 was still in stock wiring.
   If they are not connected to the ECM, how the ECM come to know what's going on ??
   These all wires give negative signal once the relative function is operated, i.e. when AC button pushes "on" ECU will give negative, and these are all connected with one another.

Read the master diagram for next 6 hours.

[Xulfiqar]

Read the master diagram for next 6 hours.
[/B]

lol - hahahah, (H)

[star2]

lol - hahahah, (H)

its like a prescription i have given to him

[Xulfiqar]

nissan wiring is easy, try to decipher a subaru justy headlamp circuit - its really odd.

[SER_GTR]

Nice To See People Taking Interest In Fixing Wiring Stuff On Their Own....The Best Thing One Can Do....!!

When I Do It Back in 2007.....People Are Just Fond Of Telling Me That I Will End Up Blowing And Burning Things....!! Never Happened......But Even If It DOES...YES...I Better Burn One Thing Myself Rather Than Getting It Burned By Other And Paying For It...Doing Khuari All Around Day In Humid Climate And Spending On Visiting And Paying For Their Desirable Stuff....!!

Some Of Them Are Just Good Enough To Just Wire It On Main Sensors And Make It Run But Never Seen Anyone Yet Who Is Willing To Wire And Make All Sensors Running..And Think....MAN Its There For A DAMN Reason...!!!