What does the OBC actually do?

[Jay07]

Hey People!

with the recent problems ive been having with my car a couple of people asked if my obc was ok. I have the 6 button one, which for the last year or so looks like is on LSd as the digital display keeps going mad like its in a rave then normal again.

Does this computer do anything more than tell time, temp etc? can it affect the running of the car?

[DaveD]

no!

[Taz]

my car used to cut out whilst driving along until i changed the obc module box behind the glovebox..it has a green plug...

[E30Mark]

my car used to cut out whilst driving along until i changed the obc module box behind the glovebox..it has a green plug...

There isn't a OBC module box behind the glove box

If it was a factory fitted OBC, then this would of had the CODE immobiliser wired in to the wiring point behind the glovebox.

By the way, don't ever expect the CODE immobiliser to stop anyone from taking your car, it was not BMW's finest attempt with security...

[Brianmoooore]

There isn't a OBC module box behind the glove box

Possibly is on a left hooker! Unless the OBC loom is reversed on these?
In answer to the OP's question: The OBC can effect the cars running, as Taz says. The ignition switched supply to the ignition coil and ECU passes through a relay controlled by the CODE function of the OBC.
It's highly unlikely that a six button OBC with the problems described above is causing any running problems, but if this relay was faulty, then it could.
Wire a small 12V bulb or LED between the + terminal of the ignition coil and earth, and position it somewhere so that you can see it when driving.
Should remain steadily lit all the time the engine is running and ignition on, with just some dimming when cranking.

[Jay07]

Cheers People!

So its just there to be pretty! - The digital display keeps losing the plot and goes crazy... Anyway to repair it or get another 1?

[Jay07]

Wire a small 12V bulb or LED between the + terminal of the ignition coil and earth, and position it somewhere so that you can see it when driving.
Should remain steadily lit all the time the engine is running and ignition on, with just some dimming when cranking.

I'll give it a go when i get a chance cheers Brian

[DaveD]

i dont want to contradict antyone more knowledgble than i but he did say a 6 buutton one and they realyl dont have any function beyond a clock and thermometer...or have i missed something

[Brianmoooore]

i dont want to contradict antyone more knowledgble than i but he did say a 6 buutton one and they realyl dont have any function beyond a clock and thermometer...or have i missed something

Think you're right actually! He DID say a SIX button didn't he! And six button OBCs don't have the immobiliser/alarm function.
Really should read posts more carefully! Also I've no idea what the fault is with the car! - just says 'recent problems'.
Anyway, if it's any kind of intermittant cutting out type thing, the bulb on the ignition coil is worth trying1

[tim-ix]

Mine goes crazy now and then but works again if I press any of the buttons in and hold them for a moment. The feature I like is the thermometer.

[R9]

I'm having trouble with mine too with random resets and display madness.

I've read that the coding plugs must be correct. It must match your clock coding plug and be correct for you model E30.

This is only relevant to retrofits obviously.

[Jay07]

Think you're right actually! He DID say a SIX button didn't he! And six button OBCs don't have the immobiliser/alarm function.
Really should read posts more carefully! Also I've no idea what the fault is with the car! - just says 'recent problems'.
Anyway, if it's any kind of intermittant cutting out type thing, the bulb on the ignition coil is worth trying1
_________________

Its the same problem ive been having from the other threads of mine you have been helping me with!!

The engine is still searching for an idle/ struggling to settle/ same for the last few months... i waiting for an alternative AFM to arrive from spadge so i can cross that off my list too... the only thing im not sure how to check is hidden air leaks.. ive checked the obvious ones while stripping the top half down!! Nothing obvious there.

As for the OBC yes i have the 6 button, thanks for the confirmation that i doesnt do much besides the obvious!
The display goes mad most of the time it settles when i tap it... only for a while.. then mental again! - Need to find a cheap one from somewhere and change it out!

[DaveD]

now there was a thread that came to the conclusion that you should check the fpr...............

[Taz]

hi: brianmooore

u r right...my car used to be a left-hooker it was converted to rhd.....but the loom is still lhd.....i need to change it as my wiring behind my glovebox is a mess

[R9]

now there was a thread that came to the conclusion that you should check the fpr...............

What's fpr?

[DaveD]

fuel pressure regulator

[Jay07]

fuel pressure regulator

? hmm must have missed that Dave... let me grab my haynes... find out where it is ...

[DaveD]

this
was the thread...a long read see if it helps

[R9]

What thread.

[DaveD]

sorry

http://www.e30zone.net/modules.php?name ... hlight=fpr