pcmhacking.net

A guide for setting up a bench test/flash setup for your VX & VY Flash PCM's

What you need:-
- loom with the PCM plug ends (30-40cm is enough)
- OBD plug ( with about 10-15cm of loom with it)
- A battery or 12v DC power supply unit (i also brought a connection for my PSU that allows bare wires to be connected
- A fuse with holder (optional but a good idea, 10amp is plenty)
- A switch (not essential but can help if you want to simulate ignition ON/OFF cycles)
- 2x distribution blocks (not essential but a good idea especially if using a PSU)
- Solder and insulation taper or heat shrink

OK to get into it!

What i did first is i depinned all 3 PCM plugs to keep things tidy. once you do 10 the rest are a breeze. Heres a youtube clip from BiggVL that shows how.



All the plugs are stamped on the ends to what they are ie A1-A12 etc (you will see these stamps in the pictures)

Next you want to find all your Earths
They are:-
A5 & B5 ---------\
C6 & D6 ------- EARTH
E7 & F7-----------/
you can leave these wires in there locations or stick them back in after if youve stripped all plugs like i did.

Your 12v positives are
C12 & D12 --------12V

Your 12v iginition wire ( this can be on a switch or attached when ready to connect )
D16
I connected all my positives to one distribution block and from there through a 10 amp fuse to the + PSU and all my negatives to another block and from there back to the - side of my PSU

You then need to connect your PCMs serial data wire to your OBD connector
This is
C13 PCM ------> PIN 9 OBD

And your PCM Diagnostics wire
D09 PCM --------> PIN 6 OBD

Now the earths for your OBD
PINS 5 & 4 ------> EARTH

And last you need to connect the 12v of your OBD
this is PIN 16 --------> POSITIVE

PIN 1 is located below PIN 9
and PIN 8 below PIN 16
And when your done

CREDIT IS GIVEN TO MICK for providing all the pinouts, more can be found at
viewtopic.php?f=7&t=152&start=20

The flash pcm wiring harness's are light yellow & brown, the pink & blue are for memcal based pcms.

You can do flash pcms with just the single end wiring harness, I think I got it down to 5 or so wires.

Top write up, thanks for putting that together and bigvl for the vid and vxl67 for the notes. I'll also add that 12v at the obd isnt needed for this as our aldl interfaces power from the usb, but its worth having it incase you plug in some other tool another day and it does need it. Its worth putting it in while your building it up.

Ill also add this as a vx pinout reference.

VX L67 Getrag wrote:The flash pcm wiring harness's are light yellow & brown, the pink & blue are for memcal based pcms.

You can do flash pcms with just the single end wiring harness, I think I got it down to 5 or so wires.

I probably should have done it with some flash PCM connections but i had a spare vs loom floating around so i whopped the plugs off that and ground off the different locator slots.
Thanks VX L67 for pointing that out

antus wrote:Top write up, thanks for putting that together and bigvl for the vid and vxl67 for the notes. I'll also add that 12v at the obd isnt needed for this as our aldl interfaces power from the usb, but its worth having it incase you plug in some other tool another day and it does need it. Its worth putting it in while your building it up.

Ill also add this as a vx pinout reference.

No problem if it helps out somebody trying to build one for themselves and they find pictures useful then job done

nice guide.

Great write up thanks, and awesome you got it to work

For a minimalist loom, and all on one connector can use the following...
D6 - Ground
D12 - 12V Battery
D16 - Switched Ign
C13 - ALDL

Nice guide!
Will definitely help out a fair few.

I have the same minimal setup as VL400 does. Both 12v bat and ignition are tied together on my rig.

And aldl and gnd out to the obd port at a minimum.