13 button OBC

[Bonymaenjack]

I have fitted from new a 13 button OBC ,due to a complete rewire of the main looms I now find the following items not working or showing PPPP
1/ The code , I can enter a code remove the key then go through the normal starting procedure with the code flashing expecting for the previous 4 digits to be entered but I've found the engine will start without entering the code . what isolates the ignition when a code is entered .it is a useful tool to have so I would like it to work.
2/Range PPPP showing even though theres fuel in the tank and the fuel gauge works .
3/Temperature .PPPP
4/Speed PPPP.

I've printed off the wiring diagram from Wiki and have identified the 17 wires out of the OBC which shows that the majority are connected to the instrument cluster with the exception of the outside temperature , chime , relay box and bugler alarm control unit (which I don't believe is fitted )
Can anyone identify what wires connect to the cluster as the wiring diagram printed isn't compatible with the wires coming out of OBC .

Thanks

[Bonymaenjack]

Bump ,
Can any one advise please

Thanks

[pk1976]

Am interested in doing the same mod. Where did you get your OBC from?

[Brianmoooore]

PPPP is the OBC's generic fault code. Disconnect power, reconnect and hope.
If the CODE immobiliser doesn't work, (and the OBC isn't original equipment to your car), then there's a good chance it hasn't been connected.
A green and red/green wire from the OBC loom connect, via a two pin plug and socket, to two green wires from the car loom, behind the glovebox area, breaking the ignition 12 volt + feed to the ECU and ignition coil.

[Bonymaenjack]

Am interested in doing the same mod. Where did you get your OBC from?

Mine was fitted as original equipment .They're difficult to source now and expensive when you do find one .

[Bonymaenjack]

PPPP is the OBC's generic fault code. Disconnect power, reconnect and hope.
If the CODE immobiliser doesn't work, (and the OBC isn't original equipment to your car), then there's a good chance it hasn't been connected.
A green and red/green wire from the OBC loom connect, via a two pin plug and socket, to two green wires from the car loom, behind the glovebox area, breaking the ignition 12 volt + feed to the ECU and ignition coil.

Brian I've disconnected and reconnected on numerous occasions but with no success .The OBC was fitted from new but as we've previously discussed the replacement loom is from an earlier year than mine (pre 88) The wiring diagram on Wiki has slight differences between the colours shown and what is from the OBC loom fitted .If I could establish what wire goes to which instrument cluster pin then perhaps I could tee in and connect that way ?

[Brianmoooore]

Best wiring diagrams here: http://www.autolib.diakom.ru/CAR/BMW/
No knowledge of Russian required - just click on the boxes.

[Bonymaenjack]

Best wiring diagrams here: http://www.autolib.diakom.ru/CAR/BMW/
No knowledge of Russian required - just click on the boxes.

Thanks Brian , that looks promising

[Bonymaenjack]

Best wiring diagrams here: http://www.autolib.diakom.ru/CAR/BMW/
No knowledge of Russian required - just click on the boxes.

Apologies for coming across as a bit of a div but is this correct page ? 325i 1988 and if so how do I interrogate the information

http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig08.pdf

[Brianmoooore]

OBC is in fig. 5: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig05.pdf

[steve_k]

cheers for that link brian very very helpful

[Bonymaenjack]

Brian
Thanks for this , there are still a few discrepancies between the wiki and your link regarding the colour of some of the wiring but I have a better picture now of what supplies/feeds what .
A question though .what do you believe the "trigger output/input " and "power" refers to also the combination sw (switch)?

Cheers

[Brianmoooore]

Combination switch is the indicator stalk - BC button on the end.
Power is just that - 12 volts+. If the main colour of the wire is red, then it's permanently live. If the main colour is green, then it's ignition switched live.
The trigger wires are associated with the chime (probably).
The circuits are for US spec. cars, so there are other idiot functions included, such as seat belt warnings, etc.
Have a look at the circuits for other E30s on the site. you won't find an exact match, for the reason above, but, as you say, it gives the general picture.

[Bonymaenjack]

Combination switch is the indicator stalk - BC button on the end.
Power is just that - 12 volts+. If the main colour of the wire is red, then it's permanently live. If the main colour is green, then it's ignition switched live.
The trigger wires are associated with the chime (probably).
The circuits are for US spec. cars, so there are other idiot functions included, such as seat belt warnings, etc.
Have a look at the circuits for other E30s on the site. you won't find an exact match, for the reason above, but, as you say, it gives the general picture.

I've spent some time on this . my OBC fitted as standard has 17 wires coming from it , the wiki diagram shows 17 wires
and the russian diagram (you kindly supplied the link to) shows 15 wires
I've written down the colour of the wires from my OBC for comparison and I have the following unaccounted for
Yellow = Heater
White / Blue =Fuel Rate Input
Green/ Black = KL16
Black = Combination Switch
Brown/White =? not found
Brown/Red = Vehicle Speed
Brown/Blue = Trigger output - Chime
Grey/Violet = KLR-Power-Instrument Cluster
Grey/Red = 68K-Illumination-Cluster
Brown = Earth
Brown/Green = Fuel Tank level -Instrument Cluster
Blue = External Temperature
Brown/Violet = Not found
Brown/Grey = Fuel tank low-Instrument cluster
Brown/Yellow = Start input- Instrument Cluster
Red/White = Instrument Cluster -Chime


Brown/white
Brown/Violet

Is it advisable to splice directly into the appropriate coloured wire feeding from the OBC to the instrument cluster and relay box