$116 Used Z3 DME EWS Bubbafett Workaround

[bubbafett]

**UPDATE** Before you read any further, Looks like my idea will not work, except on a small number of Z3's. Oh well...

After spending several hours studying up. I believe I have found a workaround for all Z3's to use a eBay or junk yard DME and keep your factory keys. It is super simple. The key lies in BMW making the Z3 in both EWS ll and EWS lllD, this workaround will benefit Z3's made from 9/98-2002 the most. Steps:
1. Buy a new virgin EWS ll unit for $116 (plus tax & shipping)
2. Install used DME and new EWS ll unit
3. Align used DME and new EWS with whatever program you have or are good with
4. Start car

Basically what is happening is your taking your EWS lllD car to EWS ll, what this allows you to do is rid yourself of the EWS lllD unit which burns itself to your specific car VIN and rolling code. This allows you to use the EWS ll unit that can be aligned as many times as you like, and technically I believe since the EWS module is virgin it takes the key transponder ID, as well takes the used DME rolling code. The part number for the Z3 EWS II CONTROL UNIT part # 61358380369

Real OEM http://www.realoem.com/bmw/showparts...33&hg=61&fg=25

BMW of South Atlantahttp://parts.bmwofsouthatlanta.com/p...931&modelYear=

[z3forlife]

Sounds pretty cool. Do you lose anything else in the downgrade

[328 Power 04]

Uuu, you just stopped me from potentially many headaches. A simple EWS disable in the ECU will not do it?

I bought a spare MS42 ECU from a 328i, to play with tuning on my roadster, and was going to plug that in to read and write a full flash on it. If I do EWS align to that ecu, will it not be enough?

Strange that all this is needed because e46 people swap ecus without too much problem, and it is the same rolling ISN system.

- - - Updated - - -

Nevermind, looking at more info, either a virgin flash in the ECU, or possibly a virgin EWS will get it to work. I'm going to go with virgin flash of ecu first.

[rf900rkw]

How are you planning on getting a MS42 or MS43 DME to talk to a EWSii?


Tain't happening.

[bubbafett]

A simple EWS disable in the ECU will not do it?

Yes it should. Just looking for more options.

How are you planning on getting a MS42 or MS43 DME to talk to a EWSii? Tain't happening.

IDK, this was a theoretical idea. I was hoping others could help me flush it out. Aren't not all Z3's DME's MS 41.1?

[rf900rkw]

Euro-M52 = MS41.0
US-M52 = MS41.1
S52 = MS41.2
M52TU = MS42
M54 = MS43
S54 = MSS54



With the MS41.x and EWS2, the EWS unit memorizes the DME's secret code. on start, the DME spits out the code and the EWS matches it. The EWS can be commanded to learn a new code easily.

Wtih MS42 or higher, the DME memorizes the immutable long list of rolling codes from the EWS3 on initial powerup. On start, the EWS puts out the next number in the list, the DME does the comparison. There is no option for relearning the codes. Aligning the EWS merely tells both modules to go back to the beginning of the code list.

[BenFenner]

Yes it should. Just looking for more options. IDK, this was a theoretical idea. I was hoping others could help me flush it out. Aren't not all Z3's DME's MS 41.1?

This is what the BMW diagnostics tool shows...


BMS46 for 1.8 1.9
MS41 for 2.0 2.8 3.2 up to 1999
MS42 for 2.0 2.8 3.2 from 2000
MS43 for 2.5 3.0 from 2001
MSS50 for S50 used on Z3M
MS41.1 for S52 used on Z3M
MSS54 for S54 used on Z3M

[rf900rkw]

Here's the part of the 3.3 description from right below the part you posted.






The entire document can be found at http://www.e38.org/EWS.pdf

[328 Power 04]

Here's the part of the 3.3 description from right below the part you posted.






The entire document can be found at http://www.e38.org/EWS.pdf

So then when I reset the ISN code in the DME (write FF across in the full 512kb flash) and align EWS in INPA, am I making the DME learn the current car's code from the EWS module? Or does the EWS module go to FF and begin the counter again?

[rf900rkw]

My understading is the code table isn't stored in the 512K flash area. It, along with a few other key things, is in a separate segment that isn't supposed to be writable. Obviously some have figured out a way, hence the virginized modules on the market.

[bubbafett]

Euro-M52 = MS41.0
US-M52 = MS41.1
S52 = MS41.2
M52TU = MS42
M54 = MS43
S54 = MSS54



With the MS41.x and EWS2, the EWS unit memorizes the DME's secret code. on start, the DME spits out the code and the EWS matches it. The EWS can be commanded to learn a new code easily.

Wtih MS42 or higher, the DME memorizes the immutable long list of rolling codes from the EWS3 on initial powerup. On start, the EWS puts out the next number in the list, the DME does the comparison. There is no option for relearning the codes. Aligning the EWS merely tells both modules to go back to the beginning of the code list.

We are on the same page, however let me explain. On real OEM and BMW South Atlanta the EWS ll and EWS lllD are compatible with all Z3's, regardless of Bosh motronic. The EWS lllD sends the codes to the DME (to the rom chip) on start "marring" them forever, the EWS ll is re-flashable an unlimited number of times. The normal thing to do is flash the DME to a virgin state to re-learn from the EWS lllD. Where this potential exploit is if we leave the DME alone and replace with a virgin EDS II, would not in the alignment the two modules be synced?
(obviously BMW programs the key transponder to your VIN in the virgin EWS unit)

Best resource on BMW EWS: http://www.e38.org/EWS.pdf

[rf900rkw]

The key transponder is not part of this equation.

On EWS2 the DME initializes the communication. The DME sends the code. The EWS listens.

On EWS3* the EWS initializes, the communications. The EWS sends the rolling code. The DME listens.

So putting a EWS2 against the MS43 will be hooking two receivers together. You have to have one transmitter and one receiver..

- - - Updated - - -

If you look at the RealOEM page (or any parts page), they show a break at 09/98. Nothing anywhere says they are interchangable.

[bubbafett]

On the BMW of South Atlanta page for the EWS ll, under product fitment (it's a drop down option) all models are listed. http://parts.bmwofsouthatlanta.com/p...931&modelYear=

Here is one example:
EWS II CONTROL UNIT.

This genuine part fits your 2001 BMW Z Series (E52,E85,E86,E89) Z3 Coupe M3.2. http://parts.bmwofsouthatlanta.com/p...358380369.html

My thought was even with a EWS lllD DME with "burned in rolling codes" all you have to do in DIS or INPA is get them on the same page, basically the #1 rolling code via an alignment. Wouldn't that make them good to go?

[rf900rkw]

Yes, if you have an S52, you havea MS41.2 and EWS2. The S52 is a throwback to the old system.


AGAIN


EWS2 **LISTENS** for the code. It does not broadcast

MS42 and later **LISTENS** for the code. They do not broadcast.

When you hook the two together, neither will broadcast. They will both sit there patiently waiting to RECEIVE the proper code.

[328 Power 04]

My understading is the code table isn't stored in the 512K flash area. It, along with a few other key things, is in a separate segment that isn't supposed to be writable. Obviously some have figured out a way, hence the virginized modules on the market.

I know the address (of the initial code, not whole code table) in MS42 ecu, it's definitely in the 512kb, as well as MS43 (but I don't yet know that one).

[BimmerBreaker]

I'd trust Randy's expertise over what any parts locator says it might fit.

[bubbafett]

Yes, if you have an S52, you have a MS41.2 and EWS2. The S52 is a throwback to the old system.AGAIN EWS2 **LISTENS** for the code. It does not broadcast MS42 and later **LISTENS** for the code. They do not broadcast. When you hook the two together, neither will broadcast. They will both sit there patiently waiting to RECEIVE the proper code.

OK Randy, thanks Brother. Well give me an A for effort. --So basically the only time you can use an used DME (non flashed) is with a pre 9/98 EWS ll car. Correct?

[328 Power 04]

Yes and no. Depends on the ECU. Your S52 is MS41.2, so you can swap and EWS align.
On MS42 (m52tu) and MS43 (m54) it depends on your skills with your cables. It's possible to virginize the used ECU, but takes some work and knowledge.