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Tue Aug 16, 2022 6:07 am

I'm down to just a few loose wires on my 2003 Forester wiring harness conversion.

This time it's the OBD2 wires. I have 3 (of the 7) wires that somehow got cut and don't connect up to the ECU.

According to the diagrams I'm reading, these would be OBD2 pins 11,12 and 13

They're on the narrow row of pins (the same row as the obd2 power wire 16).

I guess I'm curious where they connect to and/or if i need them???

Their colors are: Red w/ blue stripe, light green w/red stripe, & brown with a pink(?) or maybe white stripe?

thanks.

Tue Aug 16, 2022 12:45 pm

have you checked here

https://groups.io/g/SubaruVanagon

Tue Aug 16, 2022 12:55 pm

Or if you flip it and look from the other side you have:

1 _ _ 4 5 6 _ _

_ 10 _ 12 13 14 _ _

For my 02 2.5 from an Impreza I have: (from diagrams)

1 _ _ 4 5 _ _ _

_ 10 _ 12 13 _ _ _

If you ignore 6 and 14, 10 goes to check connector and ECU : 12 and 13 are grounds; 4 goes to the check connector and goes on same color to ignition + ; 5 goes to the check connector. 1 is battery+. There is a thread online about confusion between 1 and 16 for the battery+.

Do you still have the check connector and test connectors? I left them all intact on my harness.

Edit: sorry there's no 14 on yours.

Tue Aug 16, 2022 2:04 pm

Or check this:

http://www.mediafire.com/download/p65pf4ct744lxe8/USDM_Forester_FSM_2003.zip

Wiring System/Eng.Elect.System/page WI-86

Wed Aug 17, 2022 7:14 am

Wesitarz,

you're correct....4 and 5 are the ones in question.

When you say check connector, are you talking about the green diagnostic connectors that plug into each other to set everything into test mode? "Test Mode Connector" maybe?

Wed Aug 17, 2022 9:50 am

No,the check connector is different (B79) on that link to 2003 Forester wiring diagram I sent. It shows only 6 RBl going to a dead end and nothing for 4 and 5. Maybe you just have to hookup #10 to to your ECU D 16 or 18? it looks like and see if it works. Otherwise it seems your 4 and 5 would dead end at the check connector anyway and not make any difference. I'm not sure what the check connector does.

Wed Aug 17, 2022 12:13 pm

I agree.

I found one diagram that shows #6 (red/blue) going to the Line End Connector.....which i havent been able to find a definition of what that is or does..?

Wed Aug 17, 2022 2:25 pm

To make it more confusing on my actual OBD2 connector I have the same as you: 1, 4,5,6,10,12,13 . Different from the manual.The 4,5,and 6 wires all go the the 14 pin grey check connector. I left this connector plus another unsed one intact with the harness.
Checking my other manual 4 and 5 go to the ABS control module and the check connector. Again there is no 6. Since the 2003 Forester manual has 6 going to line end,I think you can disregard all 3 wires (4,5,6)

Wed Aug 17, 2022 7:47 pm

Scrolling through more 02 wiring diagrams 4,5 might be Auto trans also so not needed ,but I found #6 going to one of the test connectors.

Thu Aug 18, 2022 7:06 am

I'll try leaving them unhooked and see what i get....

Thu Aug 18, 2022 8:22 am

Looking again at 03 Forester wiring 4 and 5 are ABS, 6 is ATrans.