316i Compact OnBoard Computer Retrofit

[championc]

Hi all,

I wonder if someone can help me with details of the parts required to retrofit a 2 button OBC into a Compact.

I know I need the following
1. The OBC Unit with thin connection wiring
2. Selector Stalk
Are there any other bits?

Also, where does the OBC connect to ? Should there be a spare socket on the rear of the instrument cluster ?


Cormac

[L84THSKY]

I'm planning on doing that retrofit this Sunday. You will need a harness to connect everything. I was wondering if there is anything behind the cluster to deal with too. I don't think there is. I can see what parts I have at home, to give you a more precise parts list. I don't have the OBC computer/clock , so I will not actually be completing this mod on Sunday.

Originally Posted by championc

Hi all,

I wonder if someone can help me with details of the parts required to retrofit a 2 button OBC into a Compact.

I know I need the following
1. The OBC Unit with thin connection wiring
2. Selector Stalk
Are there any other bits?

Also, where does the OBC connect to ? Should there be a spare socket on the rear of the instrument cluster ?


Cormac

[J!m]

I'm reasonably certain you connect to the ECU, and not the cluster. But, I don't have one and don't plan to, so I am not the authority on this...

[L84THSKY]

I think I have the BMW retrofit instructions, need to read through them again.

Originally Posted by championc

Hi all,

I wonder if someone can help me with details of the parts required to retrofit a 2 button OBC into a Compact.

I know I need the following
1. The OBC Unit with thin connection wiring
2. Selector Stalk
Are there any other bits?

Also, where does the OBC connect to ? Should there be a spare socket on the rear of the instrument cluster ?


Cormac

[championc]

With the Compact, can someone please tell me how or where does the Compact two button unit get it's fuel consumption details from?


Cormac

[1996 328ti]

E36/5 On Board Computer Installation

[championc]

You are an absolute star - thank's a million for this. I now know what I'm letting myself in for which thankfully looks reasonably straight forward.


Cormac

[championc]

Sorry guys,

One final (I hope) question.

It says on the instructions that the "vehicle data must be programmed into the unit within 36 hrs"

If I bought a second hand unit which came from a 316i, would this mean that this step would NOT be required ?


Cormac

[championc]

So I have finally finished the OBC retrofit but not quite with the ease in which I thought at the beginning. I started by replacing the stalk which was straightforward. Armed with the BMW retrofit instructions (referring to the wiring layout on the bottom of page 4, Diagram No.2,

I got the wiring loom and firstly plugged in the OBC unit (a) followed by the connector to the stalk (c). I then joined up the two earth cables (b) to any earth I could find (all earth wires were brown - I never found any Brown/Orange). Next I went for the six wires (d to i) that were to be connected to the fan connector under the instrument panel. On my car, only two strips had space to add another wire so I had to use scotch clips to join the other four onto existing clips. The instructions said to concentrate on the wiring positions and NOT on the colours. However, nowhere could I find anywhere giving a layout of the fan connector so I hadn't a clue where X182, X183, X188 etc were located so I could only go by the matching colours which worked out fine.

Now the fun started. The next one up was the fuel sensor (j). I eventuall located the connector in the footwell but it was impossible to find the cable to snip within the mass of wires. I aborted this and decided to connect it at the back of the instrument panel instead. The wire was Pin 1 on the small black 12 pin connector.

Next up was to get the cables through the bulkhead. I could not release the clasp holding the wiring loom in place. I eventually decided to punch a hole through the same plastic panel under the loom. Installing the temp sensor (n) was easy but the final piece was the TI Sensor (m)

I found the X20 connector under the battery tray. However, plug in station No. 24 was already filled. From wiring diagrams, it would appear that it should be connected to Pin 25 on the blue 26 pin connector on the rear of the instrumental panel which is what was suggested in Diagram 13.

Hopefully this will prove useful for anyone else who decides to embark on this. It's a piece of cake in hindsight. My problems were so easily solvable but I wasted ages in the first place trying to do things by the book.


Cormac

[Rich]

Super write up,

I bought an OBC for my 316 (328) compact of ebay in Germany. It comes with loom, stack, obc unit.

I imagine my install will be similar to yours, start by going by the book, then throw the book out and just wire it in. I already have an mpg wire from installing a new dash with mpg guage. I noticed the other day that I already have a temp sensor in the brake duct so i'll just need to find where the wire goes to.

Did you have any trouble with the coding, or did it just work?

[championc]

The one I bought was for the same car as mine, a 316i 1.9 so no re-coding necessary. I reckoned that any gains that I might make with buying the bits on eBay could be wiped out by a re-coding by BMW. And you're snookered if they decided to charge you a fortune to re-code it. Be prepared to sell the OBC to buy one already coded for your Compact

The Compact OBC's are very rare on the UK eBay so could get decent price there if needed


C

[John Firestone]

Originally Posted by Rich

I imagine my install will be similar to yours, start by going by the book, then throw the book out and just wire it in.

Having been in this situation before, I might instead suggest asking about what you find unclear or wrong in the BMW installation instructions. With one big exception, I haven't read much that was "going by the book" as directed by the instructions. Why? Because the instructions assume you already know "the book" and therefore leave it out!

I think you might have an easier install if you were to ask more questions: to learn the missing book and some tricks and shortcuts you won't find in it. That certainly helped me. But to do that, first one has to become socratic, recognize one's ignorance and ask questions!

[John Firestone]

Originally Posted by championc

I found the X20 connector under the battery tray. However, plug in station No. 24 was already filled. From wiring diagrams, it would appear that it should be connected to Pin 25 on the blue 26 pin connector on the rear of the instrumental panel which is what was suggested in Diagram 13.

My ETM shows X17 pin 25 as not used. X20 pin 24 is the 'ti' (fuel injection signal) from the DME.

I have a couple questions:

• Does your car have an automatic transmission?
• Is the OBC displaying plausible fuel consumption values?

[L84THSKY]

I just started closely reading my OBC instructions, was gonna install the harness today, but rained all day.

I totally agree about the X183, X184..etc identifications. You can't see any of that crap, so you MUST go by the colors. Found that out wiring Cruise Control and Fog lights.

As you mentioned the hardest part is item "J" and "M" in the instructions.

I've posted three pics detailing all the necessary data.






You're saying for item "J", tap into pin #1 of the black 12 pin connector of the gauge cluster? The kit came with a fan connector and some piggy back wiring. But you're saying I can avoid that mess in the instructions by using the gauge cluster pin#1?

For item "M", I should find it in my engine compartment? I don't see what problem that step should be. My car is a manual tranny. Can you make sure I haven't missed anything?

This seems totally backwards. The picture is showing item "M" tapping into the gauge cluster, and you said you put item "J" into the cluster. Please explain both "J" and "M" as clearly as possible.

I hate all the piggy back taps I have installed for my fog lights and cruise control. I'm not convinced all are making good contact. What I want to do is buy some of those fan connectors from the dealer, and add more spades to the current fan connectors, basically do it right.

http://www.realoem.com/bmw/showparts...49&hg=61&fg=15

Originally Posted by championc

On my car, only two strips had space to add another wire so I had to use scotch clips to join the other four onto existing clips. The instructions said to concentrate on the wiring positions and NOT on the colours. However, nowhere could I find anywhere giving a layout of the fan connector so I hadn't a clue where X182, X183, X188 etc were located so I could only go by the matching colours which worked out fine.

Now the fun started. The next one up was the fuel sensor (j). I eventually located the connector in the footwell but it was impossible to find the cable to snip within the mass of wires. I aborted this and decided to connect it at the back of the instrument panel instead. The wire was Pin 1 on the small black 12 pin connector.

Next up was to get the cables through the bulkhead. I could not release the clasp holding the wiring loom in place. I eventually decided to punch a hole through the same plastic panel under the loom. Installing the temp sensor (n) was easy but the final piece was the TI Sensor (m)

I found the X20 connector under the battery tray. However, plug in station No. 24 was already filled. From wiring diagrams, it would appear that it should be connected to Pin 25 on the blue 26 pin connector on the rear of the instrumental panel which is what was suggested in Diagram 13.




Cormac

[championc]

I made 2 connections onto the plugs at the rear of the instrument panel

"J" - onto Pin 1 on the small black 12 pin connector.

"M" - onto Pin 25 on the blue 26 pin connector.


Cormac