new e34 owner

[shadowpuck]

As the title says - I've recently purchased a '93 525i (build 02/93). I have at least a million questions - most of which are already answered via the search feature and in the various FAQ's running around....

I've had my E36 for about 5 years so I'm not unfamiliar with BMW. Having said that, many parts of the E34 are new to me.

In particular, there's one issue I've been researching and haven't found a real solid answer yet - although I suspect it's out there!

Tonight when I started the car all of a sudden the information display in the instrument panel simply stopped working. Well, it works fine - but it doesn't display any data. What I mean by this is that it appears to simply cycle through a bunch of display tests - repeatedly. Some are entertaining, but I'd rather the information be displayed there! :)

I can no longer see the odometer, trip or otherwise and the gear selection panels are in test mode. Also, the service indicators and warning message panel are testing as well. These functions all were fine literally five minutes prior and since the failure have not worked.

In reading the archives/FAQ/search - it appears this could be somehow related to capacitors on the instrument panel? Or, is this indicative of a different issue? I've not yet had any issues with the instrument panel itself - speedo, tach, temp, fuel gauges all work great....

Thank you for your time!

[632 Regal]

I would check battery voltage and then again when the car is idling, low voltage can cause all sorts of problems with electronics.

Next is the capacitor issue and connection problems, might have bad connections between the cluster and connections, use stabilant 22 or similar on reconnecting items.

[shadowpuck]

I would check battery voltage and then again when the car is idling, low voltage can cause all sorts of problems with electronics.

Next is the capacitor issue and connection problems, might have bad connections between the cluster and connections, use stabilant 22 or similar on reconnecting items.

I did a quick voltage check using the OBC test function.
At rest it reads 12.09.

I managed to forget to check it at idle so I'll need to go do that....
In my experience with my E36, that's a normal battery reading with nothing running - would others agree/disagree?

Has anyone heard of a capacitor failing where all gauges work and the LCD panel works, but just either tests continuously or displays garbage?

[pyro]

mabe the button that you press to bring up the test is permantly pushed down? try fooling with that.

[Gayle]

As the title says - I've recently purchased a '93 525i (build 02/93). I have at least a million questions - most of which are already answered via the search feature and in the various FAQ's running around....



We love you for answering your million questions via search. :D :D :D

Welcome.


Hey Jeff--Is there some reason you didn't suggest he disconnect the battery? You usually suggest that for everything. It also sounds like he is stuck in stomp test hell.

Shadowpuck--is it giving you numbers or words?

[shadowpuck]

mabe the button that you press to bring up the test is permantly pushed down? try fooling with that.

I thought I had tried that already; however, I tried it again this afternoon before starting the car. The display is fine now....

I'll keep an eye on it, but I'm hoping that it confirms something as simple as a loose connection someplace....

I was going to try the battery reboot but just didn't want to dig under the rear seat right now if I didn't have to.....:)

Thanks for the suggestions, I'll post up if it acts up again....

[shadowpuck]

We love you for answering your million questions via search.
Welcome.


Hey Jeff--Is there some reason you didn't suggest he disconnect the battery? You usually suggest that for everything. It also sounds like he is stuck in stomp test hell.

Shadowpuck--is it giving you numbers or words?

*laughs* Yeah, this isn't my first time at the Internet Forum rodeo so I try to do as much searching as possible first....:)

When it was acting up, it was giving me either complete garbage with maybe a garbled letter or number sometimes. If it wasn't all garbled, then it was just running in something akin to the Knight Rider test mode - it was quite entertaining.....lol.... ;)

[632 Regal]

Because (http://www.bimmer.info/forum/showthread.php?postid=112874#post112874)
We love you for answering your million questions via search. :D :D :D

Welcome.


Hey Jeff--Is there some reason you didn't suggest he disconnect the battery? You usually suggest that for everything. It also sounds like he is stuck in stomp test hell.

Shadowpuck--is it giving you numbers or words?

[shadowpuck]

Well, the solution was temporary - or it at least points to the real issue....

After fiddling with the reset buttons and fixing the information display the car sat in the garage for a day. This morning, the wife started the car and the information display in the cluster was totally blank...I took a quick glance and thought that the backlight still worked, but I couldn't really study it....

Since the information display seems to at least either test, work fine, or not display - I'm thinking the LCD itself is still fine....I'm wondering now about connections/motherboard/capacitors. Based upon my research, this wouldn't point toward capacitors, but certainly could go toward motherboard connections or something like that....

Anyone wanna agree or poke holes in my thinking?? :) Thanks!

[shadowpuck]

Well, the solution was temporary - or it at least points to the real issue....

After fiddling with the reset buttons and fixing the information display the car sat in the garage for a day. This morning, the wife started the car and the information display in the cluster was totally blank...I took a quick glance and thought that the backlight still worked, but I couldn't really study it....



I'm trying to gain some understanding as to how the LCD information module and the Check control module work. Any electrical/electronic experts here?

As mentioned in the previous posts, I've been having issues with the LCD information module on my E34. Most often we either get garbage/garbled text or a test mode. If that doesn't happen, then everything either works fine or is completely blank. I could live with the garbage, but it also affects the odometer - which is kinda nice to have working!

Would anyone be willing to think that the LCD module itself could be failing or have a connectivity issue based upon the symptoms listed above? The reason for asking is that the LCD module looks to be pricey, and in my experience if all the pixels will light or test then that's not a problem....

I've found posts here referencing a BMW TSB that talks about LCD cluster interference caused by an aux water pump, however, the way the TSB reads that problem was fixed fairly early in the production run - my car is a 02/93 model....Any thoughts on that?

Here's the TSB post I found: http://www.bimmer.info/forum/showthread.php?t=7612&highlight=lcd

I've installed a refurbished cluster motherboard and the problem remained. I cleaned all connections and double-checked to make sure they were solid.

After all that - at this point - am I better off just finding a cluster on ebay/salvage and swapping the whole thing? :)

[Bill R.]

http://www.bimmernut.com/%7Ebillr/images/latercluster.jpg
I'm trying to gain some understanding as to how the LCD information module and the Check control module work. Any electrical/electronic experts here?

As mentioned in the previous posts, I've been having issues with the LCD information module on my E34. Most often we either get garbage/garbled text or a test mode. If that doesn't happen, then everything either works fine or is completely blank. I could live with the garbage, but it also affects the odometer - which is kinda nice to have working!

Would anyone be willing to think that the LCD module itself could be failing or have a connectivity issue based upon the symptoms listed above? The reason for asking is that the LCD module looks to be pricey, and in my experience if all the pixels will light or test then that's not a problem....

I've found posts here referencing a BMW TSB that talks about LCD cluster interference caused by an aux water pump, however, the way the TSB reads that problem was fixed fairly early in the production run - my car is a 02/93 model....Any thoughts on that?

Here's the TSB post I found: http://www.bimmer.info/forum/showthread.php?t=7612&highlight=lcd

I've installed a refurbished cluster motherboard and the problem remained. I cleaned all connections and double-checked to make sure they were solid.

After all that - at this point - am I better off just finding a cluster on ebay/salvage and swapping the whole thing? :)

[shadowpuck]

=Bill R

Bill - thank you for that reference. Looks like I need to do some ground testing with my handy multimeter...hehe....

I'll put that on the list - it also points to the aux water pump, but the production dates are so dissimilar that I can't imagine that's the problem....
Who knows?

I've been told to ask Javier for some help.....
Javier - any clues? :)

At least this replacement wasn't a total loss - I did learn how to remove the airbag, steering wheel, and cluster from the car. That was amazingly simple...

[shadowpuck]

Well, did some more troubleshooting today. I'm fortunate enough to have a friend with a '92 525i - his cluster works fine. We put my cluster in his car and the LCD panel did exactly the same thing. Either a test program or garbage.

To my thinking, this eliminates anything in my car as being a source of the problem. Given that I've already tried a refurbished motherboard I'm guessing I'm now at something in the LCD module itself?

[shadowpuck]

Bump up for any brilliant suggestions. I've ordered a used cluster to try in my car - since mine behaved in the same way in a known good car.

The only thing I could determine is that there's some problem in the LCD module itself....

[shadowpuck]

A bump for a good reason! I have success....:)

I bought a used cluster and replaced my existing one. The used cluster had a bad motherboard, but the LCD and everything else was good. I swapped parts in and out to produce a working cluster and voila! Success!

Everything works fine now. It appears that something in the LCD module itself failed on my original cluster.

I also repaired the electric headrests on this car by using a bit of coat hanger....

Thanks again everyone that offered suggestions or just listened to my posts....:)