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Bmw e30 13 button OBC Fuel pump connector?

13906 Views 7 Replies 2 Participants Last post by  capalfie
Hello to everyone!

My name is Sasha and I am from Bosnia & Herzegovina far away from most of you, but maybe you can help me sort my 13 button OBC.
I have E30 318is M42 1990 which had 6 button obc and I wanted to upgrade,
Found great 13 button Obc offer on ebay and purchased it.

I will give you a link so you can see which parts and part numbers I have -

I folowed the writeups I found online and managed to put everything in, this kit came without temp sensor so that we will leave aside until I get the sensor for this type of wiring harness.
I tried the CODE function, but the car starts the engine every time and I can hear the fuel pump when I turn the key. There is one connector that is meant to connect somewhere to cut the fuel pump when the code option is used, and I found on the wiring diagrams:
That it should be connected to the main relay.

My problem is that I don't know where to connect this connector (Green and Green/Red wires):

I have searched the whole internet and found that there are 2 types of wiring harness for the e30 OBC, I don't know how they are different, but this harness that I have (61121373727) is not used in 318is, the harness that is used is 61121385794.

Question: Can I anyhow connect this thing to use the code feature or I need to acquire the new harness? And even with the new harness, where should I connect it to? One say it should be connected to the ECU, but this cable is under the steering wheel and my ECU is on the passenger side above the glove box (which I opened and found these connectors; what are these for):

I didn't took the whole ECU out, I just found these connectors standing there.
Also, under the steering column on the left side near the hood release cable there is one free connector with brown and blue/red wires, the blue/red one goes to the 4th pin of this c103 connector. I even tried to connect the green wires connector to this but nothing happens. When I used the code function the car started again. Here's some pic of that connector near the hood release cable:

I have a question about the obc gong aswel, I had 6 button obc with the gong that sound when the temp is low and the memo option (left on the pic), and In this kit I got diferent obc gong (right in the pic), and it didn't work when I connected it, bud when I connected mine old gong it did work, why are these diferent, in this new gong there are two connectors and mine has only one?

Thanks for any help!
Hope I will find the solution for this._a__a2_
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Hi Sasha, greetings from Uruguay.

I don´t know if you already solved your problem because it seems to be an old post. But anyway, I wanted to help...

In the picture of the two is for the euro version an the other tipically for the us version. Euro version has only temp and speed gong, while us specs has also door and belt gongs and so on...

I have an euro E30 and looks like the one on the left pictures with only one row with pins...
Thank you for the information!

It is very useful to me.

Still searching for the solutions how to make my code option work... if you have some info about it please share it with me.

thank you!
Hi Sasha,

I will just share with you what I know: to make the Code work, you need at leaat the black relay box in full working order, the computer module of course, to input the numbers for the code, and if connected...a horn connected to the relay box. Then, you need the cables, of course, two different sets, one for the early models, another similar set for post e30 models.

Once you have the whole set, you plug all together, but keep it mind you must connect one of the cables to the ECU...or to the main relay if it is an very early model... If you don´t connect it, well, the code just won´t work.

One of the ends of the cable which plugs into the computer module has also a white connector to be connected to a white connector from the ECU and there´s also a cable coming from the main relay that connects back to the end of the same cable which plugs into the computer ll see there are two white plugs there. Try it...

There´s plenty of info about this connections, you must research forum and places like this...

It took me some months to figure it out, but with patience and perseverance you ll make it!

Best wishes...
Hi Alfie,

Thank you for your reply,

I have ordered a complete OBC2 package,
OBC relay box
Upper and lower wiring harness
OBC display with 13 buttons
OBC stalk
even the horn for alarm (when the wrong code is entered 3 times)

I installed the kit and everything works fine except that I don't have the connector near the ECU to connect the the cutoff for the fuel pump.

I have searched the whole web trying to find the solutions, because usually E30 has the connector leaved near the ECU for this option, but mine doesn't (you have some pictures up on the first post to see which connectors I have and tried to connect it)

The code option works,
When I turn the key to position 2 it asks for code, and if I try to runt the car - it runs every time, no matter the code, the fuel pump works and provides the fuel to the engine; and it is not suppose to.

If I try to enter the wrong code 3 times, it activates the alarm but I can still run the car, - this is why I know that the alarm and code option works, it is just that fuel cutoff problem (I have the connector on the wiring harness of the OBC with two green and green/red wires, but just don't have a connector on the car's wiring harness to connec it to.)

Any suggestions?

Thank you all for helping me sort this problem out!
Hi Sasha, how are you?

Well, looks clear as water to me...YOU MUST CONNECT those green and green/red wires to either the ECU or the Main Relay! That was the same problem I had when I started to solve my own problem.

In my case, I had the connector coming from the ECU...what car do you have? Perhaps you should pay a visit to the Electrical Troubleshouting Manual esquematics for your model... I´ve got mine here: I hope this helps!

I remember I had the same situation, alarm and relay worked perfectly but didn´t cut the start. Problem was that some had just bypassed the relay plugging those green and green/red wire to themselves...(it is the way to bypass the relay by the way!) Please note that! :)

But if one wants the code to cut off the start then you must unplugg the green wires together and plug one of them to the ECU and the other to the cable coming from the Main my case, an 325i from 1987. In other models should be similar but each case might be perfectly different in the connection but not in the whole my point? I hope this helps you Sasha...

I will include now couple of photos that will help you see this...anyway your car might be check up some manual, even us specs will serve you!

Best regards,:)


Hi Alfie

Thanks for your reply,

"In my case, I had the connector coming from the ECU" - you see, I don't have this connector in my car, that is the thing, I even had a great opportunity to check it when I was retrofitting A/C and had to remove the dashboard.

There is no such connector as you have it near the ECU, but again, my e30 is 318is m42, maybe it hasn't got this option, but yet again, I took a wiring diagram of my ECU and on pin no. 81 it says "OBC code protection", so I suppose it should be possible to use the fuel cutoff option...

It still remains mystery how to hook up the wiring so it works on m42 engine...

Here's the image of the wiring...

Hi Sasha,

I think you are in the right path, but you must continue pushing...mmm....I do not know about the M42 engine, mine is a M20. But in the Electrical Troubleshooting Manual shows two possibilities for my model cable from the ECU and a older model just with a wire connected to the Main Relay. Do not forget the OBC relay box cuts or lets the current flows without or with the correct code input.

So either you could find how to connect a wire to the ECU or perhaps you have the chance to connect a direct wire to the Main Relay...

But I am lost now, I have no clue about the M42...

I was just trying to help you...

My best wishes!
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