OBC fault - tried all i can think of please help!!

Post Wed Sep 21, 2005 8:26 pm

While driving today i noticed the OBC display was not showing any data, just PPPPm and PPPPm/g etc.
Is there a simple fix, or am i going to have to get the wallet or multimeter out?!
Cheers

Post Wed Sep 21, 2005 8:28 pm

sorry to hijack thrad and not be helpful

but just out of interest dude, do u have a coding plug for your OBC or are u using the 325i one?

what MPG reading u getting on the OBC for your IS

mines averaging 14

Post Wed Sep 21, 2005 8:35 pm

My OBC was factory fit, and i'm getting about 32mpg average, and that aint being light footed either!

Post Wed Sep 21, 2005 8:36 pm

is that 32mpg OBC reading?

i hope to god im not averaging that an that it is just the coding plug :lol:

Post Wed Sep 21, 2005 8:41 pm

Post Wed Sep 21, 2005 9:23 pm

according to the handbook, PPPP or AAAA means contact BMW - apologies if you already knew that

presumably PPPP means quite expensive, as in 'PPPPardon how much?'
whereas AAAA is so expensive you just scream.

Post Wed Sep 21, 2005 9:41 pm

Disconnect the battery for a short while.

Post Wed Sep 21, 2005 9:46 pm

I shall give it a go - cheers brian

Post Wed Sep 21, 2005 9:49 pm

Jamesb318is wrote:I shall give it a go - cheers brian

No guarantees, but its cheap.
Make sure you have radio code, and the ECU will probably need to relearn settings for a few miles afterwards.

Post Thu Sep 22, 2005 6:58 pm

Hi ,had the same trouble not long ago after the battery was disconnected,
tried leaving the battery off overnight and all the suggestions from my local dealer but nothing ! the only thing i found that worked and has done so twice now is to unplug the connector from the back and then plug it back in while the ignition is on this seems to flash it back to life !! i dont know what the risk of popping the obc is but it worked for me !

cheers ,paul

Post Thu Sep 22, 2005 8:04 pm

Right, leaving the battery disconnected has improved the situation, but not by much!
Now i can get the obc to display the time etc, but the mpg and range dont display (just dashes) and the temp keeps showing -30 f.
I have tried unplugging the middle connector on the rear of the instrument cluster, but this had no effect

Post Thu Sep 22, 2005 9:12 pm

Jamesb318is wrote:Right, leaving the battery disconnected has improved the situation, but not by much!
Now i can get the obc to display the time etc, but the mpg and range dont display (just dashes) and the temp keeps showing -30 f.
I have tried unplugging the middle connector on the rear of the instrument cluster, but this had no effect

-30f on the OBC sounds like the temp sensor is disconnected,or more likely a poor connection somewhere.
My OBC shows dashes on MPG and range when the battery is reconnected, but I think it sorts itself after a while. Can't remember having to push any buttons anyway.

Post Thu Sep 22, 2005 9:31 pm

That does sound feasible, but if the temp sensor went down or had a break in the wire somewhere, why would it effect the whole obc (making it show 'pppp') in the original fault?
It is weird that the other readings dont display a reading at all (ones that need external data like fuel etc.), while the temp display shows an incorrect reading

Post Sun Sep 25, 2005 4:47 pm

Hi ,again that is the same as mine ! i had to pull the connector from the bottom of the obc ,the one with the locking slide in the centre ,plugged it back in with the igntion on and it worked fine.

cheers ,paul

Post Sun Sep 25, 2005 5:51 pm

Cool, i'll try that, thanks. (next weekend though, just done a rear wheel bearing and cleaned the leather, thats enough attention for the IS this weekend!)

Post Sun Sep 25, 2005 7:23 pm

Jamesb318is wrote:Cool, i'll try that, thanks. (next weekend though, just done a rear wheel bearing and cleaned the leather, thats enough attention for the IS this weekend!)

yeah ,you can have enough of a good thing ! its a bit fiddly having to pull the heater /switch panel forward to get at it ,those two lower screws are such an ar#e to get at !

Post Sun Sep 25, 2005 9:17 pm

mmmm... great, i shall look foward to it! cheers

Post Sat Oct 01, 2005 2:54 pm

Right, just unplugged the obc and re connected it and........ NOTHING!
still has the same fault! What else can i test? This is really getting on my tits now!

Post Sun Oct 02, 2005 12:11 am

Could be quite simply it's knackered of course!

Post Sun Oct 02, 2005 8:00 pm

Thats what i feared, oh well! Time to find out the comedy price from the parts dept then search elsewhere!