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Discussion Starter · #1 ·
I am curious and would like to know how to pair up cas and ews. Let me elaborate, does cas and ews have to have the same number. Example, can a cas3 be paired with a ews2 or maybe a ews4? Or can cas2 be paired with ews3. Or does the system need to be paired as such with matching numbers? Example, cas2 and ews2 for it to work properly. I noticed when looking at used cas modules for sale that it is never specified what ews is programmed into the unit. Is ews able to be updated like a cas unit can be updated?

thanks for your replies,

Beastie645
 

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Unless you can't crank your engine, leave this alone. There is not really any advantage in upgrading either module.

The CAS manages the locking function & starting functions on the car.
The EWS manages the transmission on the car.

If either module does not communicate with the other module, the engine will not crank. Both modules communicate with many other modules to keep the car running properly. There are roughly 40 modules on the 645, & changing any module, will effect other linked modules ability to work properly.
 

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I am curious and would like to know how to pair up cas and ews. Let me elaborate, does cas and ews have to have the same number. Example, can a cas3 be paired with a ews2 or maybe a ews4? Or can cas2 be paired with ews3. Or does the system need to be paired as such with matching numbers? Example, cas2 and ews2 for it to work properly. I noticed when looking at used cas modules for sale that it is never specified what ews is programmed into the unit. Is ews able to be updated like a cas unit can be updated?

thanks for your replies,

Beastie645
The 1st two sentences of your post automatically kicks you out of the game. :)

You have not made it clear what the basis of your question is about…but it is clear (not in a bad way) that you really don’t have a grasp/understanding of EWS & CAS…and how these systems underlying operations work and how they are interconnected.

The numerical allocation of these modules eludes to which iteration it is based on model/model year. The 1st iteration of EWS started in the early 1990s…and EWS II debuted Jan/1995. CAS didn’t come along until the new generation BMWs came around (E90/E60/E65/E70/etc). So their “numerical” nomenclature don’t align due to when they came into production.

The whole idea of “pairing” is really what make it difficult to understand where you are going. Due to encryption and ISN (individual serial numbers) that are coded into these modules and are VIN specific…”pairing” used EWS & CAS modules isn’t really a “thing”. There may be some relevant “hacks” of these early modules…but it requires a thorough understanding of how these encrypted modules work and communicate over the car’s bus system. And again, the 1st two sentences in your original post indicate that you may not have a good grasp of what these modules are and how they operate in the whole scheme of the car’s starting immobilization and central locking/anti-theft parameters.

Here’s some BMW tech info that discusses EWS 4 & CAS 3 which is found in some BMWs from around the 2003-2007 era…but not all. For instance, the e39 was still around in 2003 and it still used EWS III and didn’t have a CAS module…as well as the 2004-2006 (LCI) E53 X5.

Font Document Screenshot Number


The chart below shows when EWS I debuted (1/94) all the way up to EWS III D used in the Z3

Font Parallel Pattern Rectangle Number


Font Parallel Rectangle Number Document
 

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I am curious and would like to know how to pair up cas and ews.
I'm no expert on this stuff, and I'm not sure that I understand what you are asking, but ...

See pages 10-11 in the document that I linked above. It says that one version of CAS has EWS3.3 embedded and it talks to the network via the "K-CAN" bus. It then says that CAS3 has either EWS3 or EWS4 embedded and uses the "CAS -Bus". The fact that the different CAS versions use different communication protocols makes me believe that each version of CAS is probably not interchangeable because the wiring and pinouts are probably different. If that is true, then if your car uses CAS3, you have to buy a replacement CAS3 (and not a CAS2 or CAS4).

The fact that CAS3 has either EWS3 or EWS4 seems to answer some of your question.
 

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You will need INPA, ISTA, Toolset 32, or a high end diagnostic reader than can relink the 2 modules. One this is done, the engine will crank. If you replaced either module, the serial number for that module must be changed, to match the serial number on the car. This can be done with WINKFP or ISTA, which allow you to reprogram the module to match your car. All of the programs are BMW software. The dealer will not do this, as they will only sell you a new module, & them installing it. IF you find a local BMW German car shop, they can probably do this for you. If you have to replace the CAS, you will need new keys to match the CAS.
 

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Even if you know about:
  • the SOPT function
  • the 128-bit EWS4 Secret Key
  • the ISK
  • the ISN
....you'd have a leg up on most.....but I'd claim you still would not be able to Frankenstein a CAS system (CAS/ZAS, CAS2, CAS3 or CAS3+) together on your own.

Unless you are doing "cryptology + firmware development + have MCU knowledge + CAN Bus expertise" as a profession, save yourself the frustration and find another hobby, one that has a higher ROI. If you are doing cryptology as a profession, this is probably the wrong forum to help achieve your goal.
 

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Can you tell us what document(s) this information comes from? An internet link would be even better?

Edit: The first part can be found on page 22 of this PDF document:
https://www.meeknet.co.uk/E64/04_Car Access Systems.pdf
Here’s a link to the early EWS tech info:
 
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Unless you are doing "cryptology + firmware development + have MCU knowledge + CAN Bus expertise" as a profession, save yourself the frustration and find another hobby, one that has a higher ROI. If you are doing cryptology as a profession, this is probably the wrong forum to help achieve your goal.
We will probably never know since, Beastie645 will probably never interact with this post again but, he didn't actually say that he wanted to learn how to do it. He seems to be searching for a used replacement for a CAS or EWS module. He might think that he can buy the module and pay someone to do the configuration.

Do you think that somebody (not working for BMW) can do this module configuration? Apparently, the tools to configure things in a "all keys lost" situation can be had for about $400+. That seems similar in complexity to me.
 

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Do you think that somebody (not working for BMW) can do this module configuration? Apparently, the tools to configure things in a "all keys lost" situation can be had for about $400+. That seems similar in complexity to me.
There are several entities that been successful in understanding and resetting 5 more ID's in BMW's CAS modules and modifying the associated DME/DDE modules to accept the new ID's. Their hardware/software set up are readily available on the internet.

The original OP wanted to "Frankenstein" a system together, and not sure why anyone would see the value in doing this.....if the CAS module could be programmed out of a vehicle, it would make stealing a BMW really, really easy. The purpose of the marriage of the CAS module to the DME/DDE is done to deter theft, and that system must be smarter than the average Joe.
 

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A new or used CAS must have matching keys, linked to the CAS. There are some people that can take a used CAS, & program keys to work for it, but the CAS must be shipped to them to do this. Once this is done, the CAS/EWS sync must be performed. I am sure most German cars are the same, & newer US models are probably starting to follow this path.

There are a lot of new owners with BMW's that don't understand why BMW cars don't work like US cars? There is a reason why used BMW's seem like a good deal, until they find out what the repair cost are! I am sure most of us have been down that path, & have a better understanding why they seemed like a good deal. If you can do your own repairs, the cost to repair them is must cheaper.
 

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There are several entities that been successful in understanding and resetting 5 more ID's in BMW's CAS modules and modifying the associated DME/DDE modules to accept the new ID's. Their hardware/software set up are readily available on the internet.

The original OP wanted to "Frankenstein" a system together, and not sure why anyone would see the value in doing this.....if the CAS module could be programmed out of a vehicle, it would make stealing a BMW really, really easy. The purpose of the marriage of the CAS module to the DME/DDE is done to deter theft, and that system must be smarter than the average Joe.
We are in the E63/E64 forum, so I assume we are talking about E6X. Stealing a E6X BMW became "really easy" by 2012 for the right people (see: Gone in 360 Seconds Hijacking with Hitag2). Now, 10 years later, their is not such an incentive to steal E6Xs, so the smart people no longer target them.

I believe that BMW programed the CAS module "out of the vehicle" when new, so someone else may have figured out how to do it. I don't see why this "Frankenstein" thought experiment can't be done by reflashing the CAS with alternate BMW factory software (for example: buy a CAS3 from a E46 or E90 and then program it with E63 firmware). I don't see any need for writing your own micro controller firmware.

In the "all keys lost" situation, the fix involves sending both the CAS and the DME, which suggests to me that the CAS and DME can be remarried"

Yes, I admit that the "average Joe" isn't going to do this, but is it possible?
 

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Discussion Starter · #15 ·
Herb, if you have that guy in Cali’s contact details it would be appreciated.

Hello to everyone! I have not disappeared, I am still here and still working the problem of the all keys stolen problem with my 645ci. I did purchase a used cas unit with two matched keys. The car turn over but does not start. Turns out the unit was from a 530D. A model not sold in the USA. I did change the serial number and code to cas2 but the coding failed. Turns out that the unit is a cas3.
As far as bmw standard tools software is concerned, erase it from your computer and go buy the software package from BIMMERDIAG.UK. Visit there site they have plenty of items for this. Load it onto your computer and it all works perfectly! No hassles whatsoever! Has more tools than mikes and the geeks and no issues! They are professional software developers that created this and it is very affordable.
Key programming, there are plenty of programmers available for purchase but you have to run a gauntlet in order to get this done simply because there are no published manuals for how to use them! I had to do plenty of searching on the dark web to find these publications! They are not readily available.
What you need to know before you get started. Go to Transpondery.com and research your car and learn what cas/ews your car has. This site will tell you exactly what transponder chip you will need to purchase. It has a public database for E/F series BMW’s.

Next you need to know what eeprom chip is on your cas circuit board. This will determine which programmer you can use. Easiest way is to remove the unit and get a picture of the chip with you smart phone. The number can be difficult to read.

I will continue in my next posting

Beastie645ci
 

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What you need to know before you get started. Go to Transpondery.com and research your car and learn what cas/ews your car has. This site will tell you exactly what transponder chip you will need to purchase. It has a public database for E/F series BMW’s.
BMW 5-Series
E60, E61
2004-2010
Transponder Philips Crypto 2 / ID46 / PCF7945 / PCF7936. CAS2, CAS3, CAS3+ systems.
OEM Key: 5WK49145, 5WK49146, 5WK49147, 65951301B, 66126986584 and others.


This is what they show for my E60 - I suppose this means the transponder is the same for CAS2, CAS3, CAS3+?
What are the OEM Keys for, please?
 

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Discussion Starter · #17 ·
Once you know your cas/ews, eeprom chip part number and transponder chip part number you can determine what programmers you need to purchase. If your not in a big hurry then AliExpress is you best bet for lowest price because all these units are made in the PRC.
Doesn’t matter if you are just making a new copy of a key or have lost all keys. Read the sale page and verify that your cas/ews, eeprom chip and transponder chip are included in the description. For example the AK90 programmer is only $25, but it can not service certain eeproms! You will need a R270 eeprom read/write device for older cas and cas2 cars and you will need to solder wires to your circuit board. Newer chips usually have a connector to use with the AK90 unit. The AK90 only programs the original or clones of the original 7930 and 7935 chips! If your chip is a higher number then you will need a different set up. The Hitag2 and Gambit programmers handle many different chips and also different makes of vehicles but you must use the correct chips! The chips must be originals or clones of the originals! Do not make the mistake of using aftermarket chips with additional features! Example X-Horse makes chips that are compatible with almost every vehicle but you must use X-Horse programmers or the chips will destroy themselves when you try to program them!
Right now the best combo seems to be the Hitag2 or Gambit programmer in combination with the BMW Explorer or a clone of the BMW Explorer called the E F Scanner. This combo works well if you are cas2 or higher.

Beastie645
 

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Discussion Starter · #18 ·
BMW 5-Series
E60, E61
2004-2010
Transponder Philips Crypto 2 / ID46 / PCF7945 / PCF7936. CAS2, CAS3, CAS3+ systems.
OEM Key: 5WK49145, 5WK49146, 5WK49147, 65951301B, 66126986584 and others.


This is what they show for my E60 - I suppose this means the transponder is the same for CAS2, CAS3, CAS3+?
What are the OEM Keys for, please?
I believe that the last two numbers ( 65951301B, 66126986584 ) are the cas module part number for certain cas2 vehicles especially the last number. I can only assume that the other numbers ( 5WK49145, 5WK49146, 5WK49147) are for cas3 and higher equipped vehicles.
 
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