Retro-fit On Board Computer

[cn55]

Hi All
Has anyone retro fitted an On Board Computer?? I have just purchased a second hand one and wish to fit. I see from posts from sometime ago that it is possible but the unit needs to be 'Coded' with the car. How do you do this??? Its the later round computer.

Where does the external temperature sensor fit? Assume its behind the front bumper somewhere but where does it plug into?

Any help appreciated.

Chris

[kkkrisss]

I also purchased BC with the idea to retrofit. Still have not done it.
Realoem says that all Z3s have the necessary wiring but I have not checked yet.

[Daz3]

I presume bmw will have to code it to your car I too remember seeing a post somewhere about this. As for the sensor there should be a recess in the bumper grille for it to fit and I'd have thought the wiring connector would be somewhere near on the loom? Not very helpful I know but might just be a case of searching for the sensor plug.

[lebigmec]

I have been thinking about trying this retro fit too. Has anyone got any info about what is involved,please?

[sirius-c]

I also purchased BC with the idea to retrofit. Still have not done it.
Realoem says that all Z3s have the necessary wiring but I have not checked yet.

I've currently got got my centre console and glove box out etc and have looked all over for the obc plug but its not there. Mines a 1997 2.8 roady

Sent from my Hudl HT7S3 using Tapatalk

[sirius-c]

Where does the external temperature sensor fit? Assume its behind the front bumper somewhere but where does it plug into?

Any help appreciated.

Chris

On my 1997 2.8 RHD its located here:-
Stand in front of car with bonnet up,
Strike an imaginary line vertically down from the right hand side of the drivers side headlight, just behind the bumper (inside face) there's a small hole that the sensor clips into.

As for the wiring plug mine is tied to the wiring entering the drivers headlight on its left hand side looking from the front. From memory I think its yellow but could be blue

Sent from my Hudl HT7S3 using Tapatalk

[kkkrisss]

I also purchased BC with the idea to retrofit. Still have not done it.
Realoem says that all Z3s have the necessary wiring but I have not checked yet.

I've currently got got my centre console and glove box out etc and have looked all over for the obc plug but its not there. Mines a 1997 2.8 roady

Sent from my Hudl HT7S3 using Tapatalk

I suppose it should be near the clock plug...coz this is where the BC plugs in

[kkkrisss]

here is what realoem says:

http://realoem.com/bmw/showparts.do?mod ... g=62&fg=95

I guess it would be great if someone can get hold of these instructions
from
the Aftersales Assistance Portal (ASAP)

[Brian H]

From memory the plug you are looking for is a black multi pin plug, 10 pins or so, oblong in shape with a swing clip on the back, the location of the plug should be just behind the console where the switches are placed. There is a module (airbag I think) that sits just behind the console switches, there are a lot of plugs etc that come up at his point, sometimes they are just hiding under the carpet. With regard to the OBC, if you buy a new one it will need to be coded to the car however if you buy a second hand one it will already be coded (maybe not to your specific car but it will be coded). I know at least one member that has had to change their OBC and it was just plug and play, swapping old for new.

[kkkrisss]

From memory the plug you are looking for is a black multi pin plug, 10 pins or so, oblong in shape with a swing clip on the back. With regard to the OBC, if you buy a new one it will need to be coded to the car however if you buy a second hand one it will already be coded (maybe not to your specific car but it will be coded). I know at least one member that has had to change their OBC and it was just plug and play, swapping old for new.

The question is - are there two plugs - one for the plain clock and one for the OBC in every Z3?

[Brian H]

The question is - are there two plugs - one for the plain clock and one for the OBC in every Z3?

To be honest I do not know, however I have not heard of the cars being equipped with 2 different wiring looms, it does seem as if a standard loom was used throughout and the connectors that were not used were tucked away.

[kkkrisss]

The question is - are there two plugs - one for the plain clock and one for the OBC in every Z3?

To be honest I do not know, however I have not heard of the cars being equipped with 2 different wiring looms, it does seem as if a standard loom was used throughout and the connectors that were not used were tucked away.

According to realoem you do not have to buy additional wiring so the connector must be tucked away somewhere...
Still cannot find these instructions mentioned in realoem.

[lebigmec]

So, is it just a case of fitting the OBC, a compatible indicator/dip switch & the outside air temp sensor to get it going, or is there anything else to fit? (And getting the OBC coded at a bmw dealer?)

[kkkrisss]

So, is it just a case of fitting the OBC, a compatible indicator/dip switch & the outside air temp sensor to get it going, or is there anything else to fit? (And getting the OBC coded at a bmw dealer?)

At least this is what realoem says.
However it seems nobody here has done it...

[Thesurveyor]

If it helps anyone, my computer (1998 pre facelift 2.8) was borked when I got the car and I bought a new (used) one from a breakers.
No coding or anything it just worked straight off and the readings seem sensible, even the frost warning bongs as it should.
I think they are coded to the engine size rather than the individual car.

[lebigmec]

If it helps anyone, my computer (1998 pre facelift 2.8) was borked when I got the car and I bought a new (used) one from a breakers.
No coding or anything it just worked straight off and the readings seem sensible, even the frost warning bongs as it should.
I think they are coded to the engine size rather than the individual car.

Thank you, that's helpful. I wonder whether it was because the computer was already coded, or because the car had already had one fitted & was coded?
My car hasn't ever had one before, so I guess that may be a different scenario...?
It would be interesting to know whether it's the car or the computer that needs the code...

[Brian H]

Whilst routing around in a Z the other day I took this pic of the loom running down the side of the centre console, maybe worth having a look for the OBC connector here?

[sirius-c]

well, after thoroughly searching behind the dash and console area and not finding the elusive OBC plug, I decided to give up.
Not to be defeated though I decided to have a lengthy internet search session to try find the location and ended up on a Polish forum. After translation. it turned out a guy found his tucked under the Automatic transmission bits n bobs.....
I found mine in the same location
If you look at the pic that Brian H has posted above this post, it was located at the top right hand corner...it was wedged deep underneath the auto transmission bit.

While I was there i also found 2 x black small rectangular connections, one has 2 wires to it, the other has 4 wires to it. they are attached to the same loom as the sun roof switch, heated seats and ASC switch.
I was wondering if someone might know what they are for, Im guessing that they are for something that plugs into the centre console


They are similar in size and shape to these:-

[kkkrisss]

is it possible to reach the OBC plug without removing the center console?

[Brian H]

Thanks for the update sirius-c, good to know the connector for the OBC is in the car.

[sirius-c]

is it possible to reach the OBC plug without removing the center console?

Possibly but my guess after changing hvac bulbs by entering via drivers side was extremely difficult, you'll probably be feeling around blind. I'm not at home this week so can't confirm but it might be possible by removing the auto shift Plate./gear gaitor

[sirius-c]

Thanks for the update sirius-c, good to know the connector for the OBC is in the car.

Not sure if this is relevant but just for info mines a pre facelift 1997 2.8 and the plug is there.

I'm awaiting a new mtec steering wheel so I'll be fitting the bc stalk when that arrives...I'm assuming all the plug sockets are there for that.

Just to confirm...the temp probe socket can be found here:-
Stand in front of car,
Lift bonnet,
Follow a vertical line down from the right hand side of drivers headlight (rhd),
It's behind the bumper in the black plastic.

The wiring on mine was taped up behind the drivers headlight,
It's yellow and had a black rubber bung in it

[kkkrisss]

Thanks for the update sirius-c, good to know the connector for the OBC is in the car.

Not sure if this is relevant but just for info mines a pre facelift 1997 2.8 and the plug is there.

I'm awaiting a new mtec steering wheel so I'll be fitting the bc stalk when that arrives...I'm assuming all the plug sockets are there for that.

Just to confirm...the temp probe socket can be found here:-
Stand in front of car,
Lift bonnet,
Follow a vertical line down from the right hand side of drivers headlight (rhd),
It's behind the bumper in the black plastic.

The wiring on mine was taped up behind the drivers headlight,
It's yellow and had a black rubber bung in it

Great info.

Please keep us posted.

[siwilson]

Lots of info on the US boards for OBC retrofits. Here is a good link.