Cluster / gauges interchange

[84318i]

Hi,

So I've been reading all that I could about the e34 clusters, and I understand there are 3 generations of them...mine is the early grey back as my car is and 89 535i manual.
Temp gauge and tach and LCD section showing mileage works 90% of the time, but the fuel gauge and speedo only works about 10% of the time if that. A good wack on the side of the dash usually makes the gauges work, for a little bit then they stop again. ... this tells me at least cluster IS getting speed signal and fuel level sender signal. I am relaying on the OBC computer to tell me how much fuel I have left, so that also tells me the sender is working and the issue must be in the cluster right?

I've replaced 5 electrolytic caps today per the guides shared on this forum and other sites...was pretty straight forward and cap values were standard so it was no big deal. Unfortunately, this didn't fix the issue with the Fuel gauge and Speedo.

So, I've started looking at the fuel gauge / speedo unit interchanges on realoem.com and it appears that ALL gauges with the exception of Tach/econometer interchange over the years/and models of E34 cars no matter what engine is in the car! Even the LCD panel interchanges as well.

Obviously clusters are different, some have coding plugs specific to the engine you have and some like mine do not as it's part of the harness (from what I've read).

What I would like to confirm before I troubleshoot this further is the following

1. Is it possible to use the LATE model (say 93-95) blueback cluster in the car that originally came with the Early style/brown back cluster? Since my harness has the coding plug, but the BLUE back cluster has one as well, would would be the end result?

2. Is it possible to to RECODE or get a correct coding plug for the late model BLUE back cluster out of 94-95 cars and have the coding plug specific to my M30B35 engine?
If so, who can do this?

Thank you!




My notes when I looked at the cluster part numbers in my car vs 95 530i as an example

E34 CLUSTERS

95 530i build date 5/1995 automatic m60 car HE23

Cluster parts

Fuel 80L (from 9/90) = 62138350557
Fuel % (from 9/90) = 62138350563
RPM gauge (from 1/90 ) = 62138351011
Temp Gauge (from 2/89) = 62131388789
Speedo (from 1/90) = 62111388777
LCD Module = 62111388799


My 89 535i build date 12/88 = HD13 

LCD module = 62111382977
Superceeded by 62111388799

Temp gauge (from 2/89) = 62131378565
Superceeded by 62131388789

Fuel Gauge L (from 2/89) = 62131379778
Superseded by 62138350557

Fuel Gauge % (from 2/89) = 62131378563

RPM = (from 2/89) = 62131378596
Superseded by 62131388783


Speedo (from 2/89) = 62111378581
Superseded by 62111388777

Temp/Fuel/Speedo/LCD appear to be interchangeable.
TACHometer/RPM is not .

[cirrusblau]

If you use the blue-back cluster, the coding plug attached to it will be displayed. Even though you still have your original coding plug on the harness, you will see that there are no pins on the cluster for it to plug into. Your options if you want to soldier on with the grey-back cluster is to change the speedo and fuel gauges. They can be pulled out easily.

[ross1]

Check your PMs please. I have a cluster for parts

[84318i]

If you use the blue-back cluster, the coding plug attached to it will be displayed. Even though you still have your original coding plug on the harness, you will see that there are no pins on the cluster for it to plug into. Your options if you want to soldier on with the grey-back cluster is to change the speedo and fuel gauges. They can be pulled out easily.

Was there ever a blue back cluster used in m30b35 equipped cars , 535 or perhaps 735 as they went up to 92 or maybe 93 iirc ?

And where is the coding plug located exactly on the early cars with the Grey-back clusters as it's not on the back of the cluster ?

I'd like to use a newer cluster as they are more readily available vs grey-back...but want everything to work including displaying correct mileage .

[cirrusblau]

The coding plug for the grey back is on the harness itself. When you remove your cluster you're gonna be pulling out 4 connectors. You'll notice on the brown connector the coding plug. On later harnesses that space would be emplty. As for the years, maybe late 535's were fitted with blue back cluster.

I've seen on ebay a whole board (reman) for grey back cluster being sold for $150. Maybe that could be an option for you?

[84318i]

I did pull the cluster yesterday when I soldered new caps and didn't see a coding plug on the harness plugs , I'll take a look again today .

Can the coding plug from the harness be removed , so that the plug in the blue back cluster be used ? I can then interchange the LCD module from my original cluster to retain correct mileage information ? It's not clear to me what would happen if you install a later cluster with the coding plug into a car that already has a coding plug outside the cluster in the harness ?

I've seen the board on eBay, but who knows if it will fix anything as there are two boards in the cluster or it could be the gauges so I need to do more troubleshooting to determine where the problem is.

Anyone seen a blue back cluster used in 535/735 cars ?

[cirrusblau]

Here's a picture of the brown connector.



The black thing there is the coding plug. On later harnesses that would be empty.

Have you already read this?

http://www.exx.se/maintenance/instrument_cluster_e34/index.shtml

[84318i]

If you use the blue-back cluster, the coding plug attached to it will be displayed. Even though you still have your original coding plug on the harness, you will see that there are no pins on the cluster for it to plug into. Your options if you want to soldier on with the grey-back cluster is to change the speedo and fuel gauges. They can be pulled out easily.

Here's a picture of the brown connector.



The black thing there is the coding plug. On later harnesses that would be empty.

Have you already read this?

http://www.exx.se/maintenance/instrument_cluster_e34/index.shtml

Read other posts but haven't seen that particular one, thank you !

So, it confirms clusters are interchangeable and I can simply ignore the early style coding plug on the harness (good). But, it lacks details on how to address the issue with having a wrong coding plug in your car as it handles scaling functions as the link serials . Putting a 525i or 530/540 cluster into a 535i car isn't solving the issue fully as you still need to address the wrong coding plug ...

[Jackson42]

And by changing the cluster, are you simply trading one flaky cluster for another one? I've had very good success refreshing clusters on E30s and E34s by reflowing the solder on the circuit boards where the connectors are attached, along with that on the pads where the gauges mount. If you're handy with a soldering iron, and since you've already replaced the caps, it sounds like you are, this is an easy job. Recommend you use tin/lead instead of tin/silver solder and remove all traces of flux before you put it back together. Good luck!

[84318i]

So, guys don't by what realoem is showing as interchangeable parts . The physical layout of the gauges in the early cluster vs blue do NOT interchange . I'll post pictures later when I am done working on this, but they are not physically the same (pins are different from early vs late, LCD panel is also different ).

I am good with soldering , learned how to solder when I was a teenager and can read schematics and made many projects so that part isn't an issue .

The concern was trying to use late model cluster parts as part of troubleshooting and that is a no go.

[84318i]

So, I picked up a spare Gen2 and Gen3 clusters so I have one of each. Here is what I found out -

1. gen1 gauges are completely different from gen2 and gen3 , the physically don't interchange .
2. gen2 and gen3 cluster parts appear to be the same form factor, so they most likely interchange.
3. gen1 LCD board is again different form factor vs gen2 and gen3
4. gen1 cluster board is also different from gen2 and gen3 clusters.
5. gen1 speedo is way different than gen2/3, it has a small PCB as part of the unit and it also has electronics caps , same ones that go back on the main cluster board. So, I am guessing here, but these are probably dead as well ..and is the reason why replacing JUST the caps on the MAIN board does not always solve the issues.

Using gen2 or gen3 cluster in the early e34 results in the wrong mileage being show as the coding plug on the cluster harness is being ignored.
Removing coding plug from the back of gen2/3 clusters and running in gen1 cluster results in "CODE-UNIT ?" message displayed on the LCD board.

Google search shows there are ways and tools to re-code the gen2/gen3 cluster coding plugs, so I am looking at this option.

[cirrusblau]

There's a fix for the speedometer. Haven't tried this but I think it's worth a shot.

http://www.bimmerboard.com/forums/posts/467642

[84318i]

I've taken the gen1 speedo apart yesterday , no blown resistors or parts but since it did have the same old caps on there I've gotten them replaced and also reflowed all solder points.

Haven't tested it yet, will do soon.