Meaning of PPPP on OBC

[Claude]

.. i know there was a lot already said about that, i read those treads but did not found out an answer.

MY PROBLEM:
I had intermittent problem with my cluster (either all gauges and display OK or all OUT), i replace the cluster board with a reconditioned one 2 weeks ago and everything work fine (no longer intermittence) until yesterday, cluster intermittence start over again and to day it is completely dead (no more digital displays, nor any gauges). I am probably due for another board :(

But there is something new for me, now it's not only the cluster that does not work but my OBC no longer operate (it only give me a PPPP and i can't reset with the r/s button on the OBC).

Before (when my original cluster board went out) my OBC always worked properly even when the cluster didn't.


QUESTIONS:
1- What PPPP on the OBC really means ?

2- How can i reset my OBC ? There is for sure a direct relation between my cluster problem and this bad reaction of my OBC, but if the OBC display PPPP it is certainly not completly dead ! should be able to reset it.

3- I read somewhere that we can't run the car with the cluster out, is it right ? Otherwise i may test that way if the OBC still work OK without the cluster.

I have a 535i 1989 model mars 89 (so with a separate coding plug on the back of the cluster.. a white board cover.. not a coding plug within one of the cable connectors). I have always diconnected the battery before doing a cluster removal.

Claude

[Kalevera]

It means it isn't able to acquire information from the coding chip (either in the back of the cluster or on a separate harness connector just behind the cluster) necessary to make various computations. It may also flash up whenever swapping in an OBC for a second after the ignition is on.

I'd first pull the OBC, reseat it and see if that does anything -- it probably won't. Check the plugs at the back of the cluster, they can come out as well and cause all sorts of ridiculousness. Then start thinking about the coding chip.


best, whit

[Alexlind123]

After i disconnected my battery to charge it (i left my interior light son all night and the battery was at 4 volts) and but it back in, the OBC said that for a second or two before it resumed normal operation.

[emw525E34]

You might want to go a full RESET on the OBC. Pull the battery terminals, then cross the +ve and -ve terminal for a few seconds (ie connect them together!). Connect it up properly again. +ve first, then ground cable.
PPPP should disappear. Unless Whit is right that coding plug becomes screwed for some reason.
Good Luck.

[Claude]

It means it isn't able to acquire information from the coding chip (either in the back of the cluster or on a separate harness connector just behind the cluster) necessary to make various computations. It may also flash up whenever swapping in an OBC for a second after the ignition is on.

I'd first pull the OBC, reseat it and see if that does anything -- it probably won't. Check the plugs at the back of the cluster, they can come out as well and cause all sorts of ridiculousness. Then start thinking about the coding chip.


best, whit


You're right Whit, the plugs was the cause of my problems, my OBC for sure is OK and it appear that my new cluster too.

Each one of those 4 plugs has many pins and the connexions are not reliable. If you play a bit with those plugs you may open the connexion with the OBC and get the PPPP code on the OBC as i did (confirm Whit's comments).

But by experience to day i've also got situations like those:
- the digital display freezes (all of them) and stay ON even after the key was remove from the steering, other functions (speedo, RPM, Fuel level and Temp) was OK.
- Hand break and safety buckle lights no longer lit, all other cluster functions being OK.

I tried to tape each connectors on the back of the cluster (put sme duck tape on them to stabilize the plug expecting better connexions) without good result.

I finally push a bit of WD40 on the pins (cluster side of the connexions) replugs everything and the cluster reaction now seems OK.

So if you have to disconnect your cluster for any reason, cleaning and tightening thoses connectors is a good idea to avoid further intermittence. After cluster reconnexion, consider those connectors as your suspect #1 before losing your time searching intermittence causes elsewhere.

Thanks for your comments, it really help ! Claude

[uscharalph]

.. i know there was a lot already said about that, i read those treads but did not found out an answer.

MY PROBLEM:
I had intermittent problem with my cluster (either all gauges and display OK or all OUT), i replace the cluster board with a reconditioned one 2 weeks ago and everything work fine (no longer intermittence) until yesterday, cluster intermittence start over again and to day it is completely dead (no more digital displays, nor any gauges). I am probably due for another board :(

But there is something new for me, now it's not only the cluster that does not work but my OBC no longer operate (it only give me a PPPP and i can't reset with the r/s button on the OBC).

Before (when my original cluster board went out) my OBC always worked properly even when the cluster didn't.


QUESTIONS:
1- What PPPP on the OBC really means ?

2- How can i reset my OBC ? There is for sure a direct relation between my cluster problem and this bad reaction of my OBC, but if the OBC display PPPP it is certainly not completly dead ! should be able to reset it.

3- I read somewhere that we can't run the car with the cluster out, is it right ? Otherwise i may test that way if the OBC still work OK without the cluster.

I have a 535i 1989 model mars 89 (so with a separate coding plug on the back of the cluster.. a white board cover.. not a coding plug within one of the cable connectors). I have always diconnected the battery before doing a cluster removal.

Claude
Last time I disconnected my battery the OBC went PPPP and when I started to hit a couple of buttons I was able to put the date and time in.

[shogun]

PPPP means there is no communication between cluster and OBC. Maybe one of the pins of the plug where the OBC goes in is bent?
E34 OBC into E32: Basically an OBC from a E34 will fit, if it has a high cluster = the cluster has the check control and the chip. If it does not have a check control = low version, then the E34 OBC needs a chip into the back.
These low versions were mainly sold in Europe, not in USA.

Here some pics of a coding chip installation
http://www.gunnar525.de/screwings/bc4_umbau_codierstecker.pdf

Gale info OBC
page_2 (http://www.nmia.com/~dgnrg/page_35.htm)

others
http://www.bimmernut.com/forum/5-series-bmw/36728-another-pppp-obc-question.html