DIY: Z3 Non-M gauge cluster to Z3M S54 Conversion

[DY1126]

Thank you very much. I have sent you an email. Please check it when you have a chance.

[JBanzhaf]

DY1126,

I sent you a private message with my email address. You can send me your VIN that way.

Thanks,
Joel

[DY1126]

I’m sorry to bother you again.

I tried to send you the VIN via private message, but I was unable to do so because I do not currently have permission to send private messages.

I apologize for the inconvenience, but could you please let me know how or where I can send the VIN to you?

Thank you very much for your help

[DY1126]

Thank you for your reply.

I read the 93C56 EEPROM again, but the entire dump was filled with zeros. It seems that the EEPROM was not read correctly, or the chip itself may be faulty.

I will send you the VIN via private message. I would greatly appreciate it if you could create a corrected dump file for me.

Thank you very much for your help.

[JBanzhaf]

DY1126,

I looked though the EEPROM dumps you posted. First of all, the 93C46 coding plug looks good. It indicates a mileage of 63790. Unfortunately, the 93C56 dump from the internal EEPROM doesn't match the Z3 coding data, and seems corrupted. This likely means the internal EEPROM has failed and will need to be replaced and recoded Or you just got a bad read. But since you have an EEP_1, I'd guess it's a bad EEPROM. If you want to replace the EEPROM yourself, I can recreate an EEPROM dump that matches your car if you provide your VIN (even the VIN is corrupted in your read). You can also send the cluster to me for repair, if you would like. Send me a DM either here or on social media if you want to do that.

Thanks,
Joel

[DY1126]

Thank you for your reply.

Regarding the mileage, I’m sorry, but I’m unable to confirm it at the moment because “EEP_1” is displayed in the odometer area instead of the actual mileage.

I have attached both dump files. Could you please check them when you have a chance?

Thank you very much for your help.

[JBanzhaf]

Hi DY1126,

Send me your EEPROM dumps, and I’ll have a look at them. Also, what should the odometer mileage be?

Thanks,
Joel

[DY1126]

Hello,

This is my first time posting on this forum. I came across your thread about the E36 and would like to ask for your help. Please excuse my limited English.

I am currently having an issue with an EEP_1 error on the instrument cluster of a BMW Z3. After reading your thread, I learned that the external EEPROM may be the cause, so I read the data from both the internal EEPROM (93C56) and the external EEPROM (93C46).

Would it be possible for you to check and correct the data and send the repaired files back to me?

If you are able to help, I can send both EEPROM files via private message.

Thank you very much for your time and consideration.

[JBanzhaf]

Hi Maverick, here is the pinout for the Z3 CAN cluster. Let me know if you need anything else.

Thanks,
Joel

[Maverick_]

Hello everyone, I have a BMW E36 with an S54 swap.
I would like to install a BMW Z3 M instrument cluster, because I want to use the CAN bus functionality in order to integrate an MK60 DSC module and also get the A/C system working properly through the MSS54 DME.
I think I will be able to find a Z3 M cluster soon, but I'm struggling to find a wiring diagram or pinout for it.
Could anyone tell me which pins on the Z3 M cluster are CAN High and CAN Low, or point me to the correct wiring diagrams?
My goal is to use the cluster as the CAN gateway between the MSS54, MK60 DSC and A/C system.
Any help would be greatly appreciated.
Thank you!

[nesterkyn]

I just rebuilt my cluster for my S54-swapped Z3. Here are the major additions:

- I used the EEPROM coding bin file JBanzhaf kindly sent me, and the chip seemed to flash on the first try using the EEPROM writer tool he recommended. I did not alter the coding plug, so the mileage tamper light was on, but I was able to sync the mileage with the trip reset button, navigating through the menus.

- I used gauge faces from Speedometer Conversion Solutions in Utah; they have black gauge faces that give more of a 'sleeper' 90s vibe.

- I installed a gauge.s from Sorek. This involved cutting the gauge faces with a razor blade, finishing the cut with sandpaper, and using some dark metallic paint to match the housing walls to the other window. This process was tedious but well worth it, the Gauge.s looks very OEM+, and I doubt 99.9% of the population could tell it is not OEM. I wired the button for the Gauge.s to a modified fog light switch, where I removed the latch, so it is now a momentary pushbutton. This lets me monitor/log all of the data on the K-Line, so for an S54, the important ones for me are Oil temp, Coolant temp, and IAT.

Huge shoutout to JBanzhaf, he made this possible for me.

[JackCob]

Quick update — I’ve managed to resolve this.

The miles/km setting is controlled in the internal EEPROM manufacturer data block, not through NCS Expert coding. I identified the relevant bytes and checksum logic and was able to toggle the display successfully.

I’ve documented the full process in a separate thread here:https://nam3forum.com/forums/forum/e36-1992-1999/e36-coding-tuning/351103-changing-odometer-display-miles-↔-km-on-bmw-e36-vdo-cluster-hw-7-1-sw-24

Thanks everyone for the input — it helped point me in the right direction.

[JackCob]

Hi Joel,

Thanks, that makes a lot of sense regarding the mileage being stored as a unit-less value. I had originally thought switching units would recalculate the mileage to km, but your explanation clears that up.

I’ll have another go with NCS Expert — I might’ve been using the wrong profile or missed something there, so I’ll report back once I’ve tried again.

I’ll also send over the modified dump that’s displaying KM (it’s only the internal EEPROM), but it’ll probably be in a couple of days as I don’t have immediate access to my workshop.

[JBanzhaf]

Hi JackCob,

Send me (or post) your modified dump that’s displaying in KM. Also, the NCS Expert method should work. You’re possibly just using a profile that doesn’t support writing. But regardless, it won’t actually convert your mileage to KM. The EEPROMs store the mileage as basically a unit-less number. So when you change the units, the number does not change to match the new units. I’ll send you new dumps with your mileage updated to the correct value in KM.

Thanks,
Joel

[JackCob]

Hello everyone,

I’m trying to convert the odometer display from miles to kilometers on a US-spec M3 cluster (HW7.1, SW24).

I’m fairly new to EEPROM work, but I’ve managed to read the cluster and successfully extract both EEPROM dumps. I’ve been working with a hex editor for about a week now, comparing my dumps against several EU cluster dumps.

I also attempted to change the unit using NCS Expert, but it didn’t seem to have any effect on the cluster.

So far, I’ve noticed that if I copy the first 64 byte pairs from an EU dump into my own, the cluster will display mileage in kilometers and the tamper dot disappears. However, it still retains and displays the original mileage in miles, with the kilometer value shown separately in the corner.

Any further modifications I’ve tried result in an “EEP-2” error on the cluster, so I’ve backed off from changing anything else blindly.

One concern I have is that the EU dumps I’m comparing against are not from M3 clusters. I’m worried that differences in configuration (such as speedometer scaling and RPM scaling) may be outside of the correct range for my cluster if I try to apply those values directly.

At this point, I’m not fully sure how the mileage, unit conversion, and checksum/data structure are tied together in this EEPROM. I’m looking for guidance on how to properly approach this conversion, or what I may be missing in terms of the correct bytes/structure that need to be modified.

If anyone has experience with this cluster or can point me in the right direction (even just concepts or what to look for in the dump), I’d really appreciate the help.

Thanks in advance.