RB20DET Diagnostic plug

[ih8hsv]

Hi,

This is my first post, so hello to you all.

I hope I can contribute here like I have done with The Australian Ford Forum, however when it comes to Nissan mods Im afraid Im a bit of a noob - therefore the reason for my first question here!

Anyway: I have recently aquired a VL Commodore. The person before me has taken out the standard 6cyl Nissan factory moter, and replaced it with a RB20DET.

For some reason it will random cut out and stall, so was hoping to check the ECU fault codes for it.

I see that the ECU has been replaced and it doesnt have the diagnostic LED light on it to check for trouble codes ( which is standard for VL Commodore ).  Ive been told that you can wire in your own Consult port directly into the ECU yourself to check for codes.

Does anyone know how to do this. I did some searches but got confused very quickly.

Any help will be much appreciated.

Thank you.

 

 

 

[GTSBoy]

RB20DET ECU has an LED. It's next to a knob that you use to trigger it.

You can also wire up the Consult port. Easy as. The RB20DET ECU wiring diagram and pinout tables are freely findable with 2s of googling. It's a serial connection - there's not a lot of pins to hook up.

[Duncan]

It's unlikely (but not impossible) the ECU will be able to tell you much about why it stalls.

When does it run OK, and when does it stall? does it ever run rough or misfire/hesitate? Is it better when cold or hot? Does it only happen when moving?

[ih8hsv]

19 minutes ago, GTSBoy said:

RB20DET ECU has an LED. It's next to a knob that you use to trigger it.

You can also wire up the Consult port. Easy as. The RB20DET ECU wiring diagram and pinout tables are freely findable with 2s of googling. It's a serial connection - there's not a lot of pins to hook up.

Thanks for the reply.

How do i wire up consult port. Sorry this is very new to me. The ECU has no led lights, Cheers

Edited August 19, 2019 by ih8hsv

[ih8hsv]

8 minutes ago, Duncan said:

It's unlikely (but not impossible) the ECU will be able to tell you much about why it stalls.

When does it run OK, and when does it stall? does it ever run rough or misfire/hesitate? Is it better when cold or hot? Does it only happen when moving?

Takes a little bit to turn over. But when it starts it runs good. But when driving it will cut out randomly. Worse when cold.

Was thinking it my be the Throttle position sensor or something. It doesnt miss so it cant be a coil

 

Thanks.

[GTSBoy]

1 hour ago, ih8hsv said:

How do i wire up consult port. Sorry this is very new to me. The ECU has no led lights, Cheers

This is a Consult port

The 3 important wires are those that connect to RX, TX and CLK. They are AF01, AF11 and AF32, respectively. Colour codes are also shown.

This is the same Consult port, now with the wiring down to the W-2 connector shown. That's the ECCS harness, which proceeds to the ECU.

You can see the same wire numbers turn up on the RHS of that plug. But you don't have to follow it from here, because....

This is a snip of the ECU, showing those same wires on pins 21, 22 & 31, in order. There's also the CHK pin on 47, which is the one you can short to earth at the Consult plug to convince the ECU to go into diagnostics and flash the check engine light to reads codes. You can see CHK in the Consult port image. But that would assume that the ECU has been wired to the check engine light properly.

Edited August 19, 2019 by GTSBoy

[ih8hsv]

Great thank you for that information.

Ill have a look in the morning and see how I go.

Cheers

[ih8hsv]

14 hours ago, GTSBoy said:

This is a Consult port

The 3 important wires are those that connect to RX, TX and CLK. They are AF01, AF11 and AF32, respectively. Colour codes are also shown.

This is the same Consult port, now with the wiring down to the W-2 connector shown. That's the ECCS harness, which proceeds to the ECU.

You can see the same wire numbers turn up on the RHS of that plug. But you don't have to follow it from here, because....

This is a snip of the ECU, showing those same wires on pins 21, 22 & 31, in order. There's also the CHK pin on 47, which is the one you can short to earth at the Consult plug to convince the ECU to go into diagnostics and flash the check engine light to reads codes. You can see CHK in the Consult port image. But that would assume that the ECU has been wired to the check engine light properly.

OK.

So I have to buy a consult port from somewhere and wire it up as you suggested - is that right?

Thanks

[Ben C34]

You could probably steal one but that would be wrong. So buying it is the better option