No Cat, No Oxygen sensor.

[ryana89]

Your advice/help is MORE than welcome, its the members on forums like these that have more knowledge and experience than 95% of local automotive techs.

Also I (we) need to keep in mind this car has had the 2E thrown into it and perhaps some wire mods along with it.
If there is another 3wire plug somwhere, then what is the 4 wire plug meant for in the engine bay!

Going to strip everything out and confirm if I've found the right plug or not tomorrow.

[ryana89]

So I was starting to get optomistic towards finding an explanation when I found this in the Bentley manaul... (Note it mentions the 4 pin/wire connector for cars after 1990)



Then I removed the ECU and looked at the connection.....






I thought Digifant was 25pin?.........Ok


I checked the continunuity of the 4 wire plug in my engine bay, to see if they matched to any of the ECU connector pins.

Remember
#1 - Green/Red
#2 - Yellow
#3 - Brown
#4 - White/blue

And here's what I found

#1 Came out on that massive ECU connection (marked green)
#2 came out on the ECU connection too (marked yellow)

Now the fun bit, wires #3 and #4 did not go to the ECU, instead they had continunuity with this plug, that is connected to nothing in my scuttle tray.....
(#3 marked brown, #4 marked white)



The 2 wire plug that is not connected to anything.....



Just when you thought it couldn't get more confusing

[peedman]

LOL yours is digi1 not digi2. I miscounted the pins, #1 is actually the bottom left and 38 is the top right. So the two highlighted pins are #10 and #27 and looking at the chart, it definately corresponds with those wire colours.

So that plug is for CO Potentiometer, and Knock Sensor!

CO Potentiometer:

A Potentiometer is used to adjust the CO mixture. The Potentiometer is located on the intake air duct before the throttle housing. A tamper-proof plug is used to prevent adjustments by non-service personnel.

An air temperature sensor is located within the potentiometer housing. The air temperature sensor is used to calculate air density.

Digifant I Pinout

As for the plug in the scuttle tray i think its for the ambient temperature sender which is why there is continuity there.

[ryana89]

LOL yours is digi1 not digi2.

Can describe how stupid I feel.......But now I can figure this out!!!!

I miscounted the pins

I was hoping so, reading what you said before you edited was a little confusing

This is making sense now!!!

EDIT: That must also mean that it IS capable of storing fault codes if its Digi 1 (correct me if I'm wrong), thing is the plug for figuring out faults is is meant to be under the gearstick boot cover, which it is not there.

[mikinoz]

How do they have the same numbers as mine but not be digi2? I'm sorry if I added confusion.

[ryana89]

mikinoz

Bosch Part# : 0 261 200 294
VW Part #: 037 906 022 M

ryana89 (me)

Bosch Part# : 0 261 200 550
VW Part # : 037 906 022 CL

Must be it?

[mikinoz]

I'm intrigued.

Here are the pin out for digi1

Digifant I Pinout

And I'm loving how much I'm learning.

How to wire your Digi I

Help with my digi 1 swap.

[ryana89]

According too the Digi 1 wire colour chart (posted by Peedman/mikinoz and also in my Bentley manual)

The 2 oxygen sensor wires and their # position (the colours/position they should be in)
Connector Pin #9 - Black Wire
Connector Pin #16 - Violet Wire

Well.......... the picture explains itself


I've gone through ALL colour charts for Digi 1,2 even Motronic and NONE of them show the wire combination shown above.

[peedman]

In my experience I wouldnt worry about colour too much as sometimes there are variations. I know it will be hard but if u can trace the wire that would be a good bet.

[ryana89]

Just did a few checks, NONE of the wires match up with the positions noted in the DF1 wire table.
For example my Blue Temperature Sensor uses a Brown/White and Brown/Green wire on connectors 13 and 14 (not what the table says).

Custom wiring????????????????

I'm just going to put it all back together and when time permits, go for a (long) drive to Sydney, as no doubt Loon would know what to do.
Thankyou for helping me, its made pullig everything down alot easier.

[ryana89]

Going to do what 2 people reccomended (before the VWW server reset) and take the MK2 to J-Mac in the new year most likely.
Again, thank you for all helping me out.