pawel129

hello everyone,
could anyone have wiring diagram (pinout) of ECU? I tried to connect rear fog lamp. When I try to trigger them by stalk, then I hear "click" from ECU (rear fog relay). In usa version trunk lamp have 2 reverse lights, but in EU left is rear fog light, right is reverse light.
I think that (maybe?) harness is another than EU, so I'd add wire to connect fog lamp with relay from ECU.
Or anyone help another solution? My IS is from USA.
Thanks!

Bertin3ISF

Interesting

Sasnuke

Hey pawel...I think I understand what you are trying to do. You want the left reverse lamp to come on as a rear fog lamp when the taillights are on? If that's correct, then I would suggest simply cutting the black wire from the left reverse lamp and splicing it onto the violet wire for the rear taillights. The rear fog light will come on with the taillights and you won't need a relay. As the left reverse lamp is a halogen bulb, maybe replace it with an LED as the taillights are LED also. If you notice in both diagrams the wires are both on the Q44 connector, so it should be pretty issue to make the new connection.

pawel129

thank you for reply, Sasnuke.
Rear fog light, in EU law, couldn't switch on with taillights (auto). They have own switch on light stalk. See more on photo, left rear lamp USA and EU. And light stalk.
As I said, rear fog light is switching by trigger switch on stalk. It's hear when relay in ECU switching on/off. ECU must have dedicate output. In fuse box is "10A RR FOG" fuse.
Sasnuke, do you have full schematic and description of ECU (wiring, harness)? Where can I download that ?
eu standard
stalk switch
usa standard

Sasnuke

Can you post a pic of where the 10A RR FOG fuse is located. Unfortunately the North American wire diagram does not even show it as none of our vehicles have a rear fog light.
I do see some empty fuse slots in the junction blocks, but none are labelled as to what they would be.

Sasnuke

Best guess without seeing where the 10A RR FOG fuse goes...i think the output wire/terminal for the rear fog light will be on connector 4D on the Main Body ECU between pins 19 to 36.
You would have to backprobe each one with the connector connected to the Body ECU and see where one has battery voltage when you turn the Rear Fog light switch from OFF to ON. (OFF=0Volts ON=12Volts)

pawel129

This is top of fuse box in my IS:

Sasnuke

Hey pawel, I looked up and down at the North American wiring diagrams and unfortunately because our vehicles don't have that feature, they don't include the circuitry in any diagram that it's possible to see. Obviously the fuse is there, and if you hear the relay click when you turn the stalk to the rear fog ON position, then it's very likely the circuit is present inside the Main Body ECU.
Going back to my previous post, using a Multi-meter to backprobe the terminals between 19 and 36 while turning the switch ON is your best bet at this time to see which wire goes from 0volts to 12volts once you turn the switch ON. It's possible there may not even be a wire in the pin hole of the connector as it wouldn't be going anywhere since both rear reverse lights have their own circuit coming off the Main Body ECU.
The good news it's only 18 pins you have to backprobe, and hopefully you find it before doing all 18. If you notice any pin locations that don't have a wire within that group (19-36), I'd probably start with those, as they are likely to be the one you are looking for.
Good luck...wish I could have been more help.

pawel129

Thank you for reply, Sasnuke.
I'll check them tomorrow. I wish that our ISs are pre-wired the same for all regions

pawel129

bingo I found it.
It's 12th pin in 4D plug. Of course it's without wire, but it's no realy problem. Just a metal pin and piece of wire to trunk.
In a few days I'll do this and make some photo.





Next question is how turn on orange light in dashboard. Green indicator (front fog light) is turning on automaticly. But orange should be when I trigged rear fog light.
Please share wiring diagram of light stalk (connector plug and socket).

Sasnuke

Hey pawel, glad you found the wire. Looks like you're almost there to get this rear fog light working.
I looked at the wiring diagram and it appears the Main Body ECU turns on the dash light via the CAN communication lines...and the Fog switch does not connect directly to the dash lights.
It's quite possible that the dash does not have the light you need as it's a North American model.
Here are the diagrams I found.

pawel129

I don't think so, because if ignition is turning on, all indicators are tested and switch on for few seconds. Rear fog light indicator too.

It's higly propably it is.

where did you get it? Is it possible to download all electrical documentation ?

Sasnuke

Wow...you are lucky you have the light. Is it possible in order for the light to stay that you need to have the rear fog light hooked up and working?
It's likely the Main Body ECU is looking for the light circuit to be grounded....I'm assuming you haven't run the wire down to the back yet.
It's possible once you have it all hooked up, and you turn the switch on, the dash light will stay on.

As for the wire diagrams...where I get them from you won't be able to. I can post some if you need...but some of them are really really big!

pawel129

I connected fog lamp and it's working. But indicator no.

Sasnuke

So close.
Do you need the dash light to work for it to be legal?

My last thought, and a complete shot in the dark, is if there is a customize-able feature that would turn on the light permanently when the fog light is in use.
I don't think it's possible, but I'll have a look once I'm back from my work trip. My car isn't with me right now.
I'll post back on the weekend whether I find something or not.