OVER CRANKING

[Southernboy]

Nope - it has a random rolling code handshake with the DME. The code changes every time you switch off the engine.
It's all part of the anti-theft system. Apparently, when you replace the EWS with a new module the rolling code has to be re-set to #1 in the DME and then the process of verification between the EWS and the DME is synchronised by the codes from there onwards. Added to that, the EWS has to be coded to your car VIN number.
The problem with trying to replace just the EWS from another vehicle is that the rolling code will not match the last code set in the DME.
The only way to replace the EWS with a second hand ews is to also replace the DME and the key and key barrel from a similar year / model car. All the components being replaced must come from the same donor car since that ensures that the EWS and DME are matched in terms of the rolling codes, and the key and EWS are matched in their coding too. The replacement components also carry the same VIN number, which is not you VIN number, but that of the donor car.

 

[handsomejackuk]

yeah i get that.. i just didnt know whether the dme was involved with the ews.. seems like it is then... its all new to me but i will get around it all when i get my key programmer back.. i just thought maybe the ews sent an electical signal to the dme to activate the dme relay...... and start the vehicle

 

[Southernboy]

I would be very interested in what you find out once you start fiddling.
There seems to be a lot of BS out there on the net.... seems like nobody is telling the full story, or it's hearsay or just plain BS.
From what I can gather the major stumbling block is the rolling code. The DME apparently can be "reset" at code #1 when fitting a brand new EWS module. So, it is obviously possible to reset that aspect there. The question arises, can a used EWS module be reset to code #1 so it is detected by the DME as being a new unit and they both kick off from scratch so to speak. Coding the keys is a simple matter and doesn't really come into the picture. It's the EWS and DME communication which ensures the fuel gets fed and the spark gets fired when the key is turned.
The only connection between the key and the EWS / DME aspect is that the EWS must recognise the key as a valid key. Once it accepts the key, it will send the new rolling code to the DME, and the DME will allow the actual ignition process to happen.
The signal to the EWS from the key is via the antenna ring around the key lock barrel. The signal is transmitted by induction to the EWS.
in other words, it isn't necessary to have a battery in the key. That is there for the central locking signal function only.
I posted a couple of links earlier which are worth a visit and a read through. The link to the company marketing "re-built" DME's is of particular interest, since they sell them to order and use the buyers VIN number to pre-program to code1 prior to delivery to the buyer.
Anyhow, if / when you get started with your tinkering, please include me on your list of people to notify that you have begun a post / thread on your progress...

 

[mrscalex]

The only way to replace the EWS with a second hand ews is to also replace the DME and the key and key barrel from a similar year / model car.

That's 100% not the case as I've already tried to say previously. I've done it twice. Once to recover the ID of a faulty EWS (sticking relay). And the second time when I carelessly mislaid the first attempt. On the second occasion I think the module came from a Land Rover as they used exactly the same system at that time. You just need a £20 secondhand EWS module of the same type and the AK90. Of course if you can't read your old EWS you are in trouble. But the nice thing about the AK90 is it piggy backs the main EWS chip and even if the chip is no longer communicating via the circuit board it will hopefully communicate with direct connections to the pins.

The consideration for you is introducing a later build of EWS. I don't know if writing the key/ID data back is also writing the old software back. Or if it doesn't, whether the format of the key/ID data from an older EWS build will work with a newer one.

But you are right. There is an enormous amount of BS written about the EWS. People like to pretend they know how it works when it's clear they haven't got a clue and are unlikely to have ever fault found/re-written one. They just regurgitate other BS they have read.

Common BS includes:

• Car cranking but not starting. "The EWS must need replacing". Wrong. If the car cranks the EWS has done it's job. It might need re-syncing to the DME but it doesn't need replacing
• The car isn't cranking. "Try changing the battery in the remote as there's a thing in there the EWS uses that needs power". Wrong. The transponder uses self-powered near field communication
• The alarm keeps going off. "Must be the EWS". Wrong. The alarm is just a loud-speaker system that is triggered if a system contact is broken. The EWS has nothing to do with the alarm
• The car won't start. "I've heard it's a thing called an EWS and it can go out of sync". Okay so far. "Touch the positive and negative terminals of the battery together to reset it". Wrong and stupid to even try it
• BMW dealer. "The EWS needs replacing". Okay so far. "You'll need a new DME and all new locks too. £3,000 please". Not only wrong but for the people this has actually happened to I'd be going to trading standards.

 

[mrscalex]

Nope - it has a random rolling code handshake with the DME. The code changes every time you switch off the engine.

It's not random. The DME has an internal table of codes it works down. When the car successfully starts the DME advises the EWS of the next code in the table. Next time around the DME says to the EWS, before I release the ignition circuit, "what was that code again - just so I know it's you?".

A resync just involves moving the position back to position #1 in the table. And the DME passing the first code to the EWS. Effectively a password reset. As best as I can tell the purpose of this is it to prevent hot-wiring. You can't hot wire without a valid EWS in the car (and transponder in the key) as it won't be passing codes back to the DME when requested. The best you'll achieve is turning the starter.

The above mechanism is not a consideration when replacing the EWS. You just do a resync after putting the replacement EWS in.

Honestly, replacing an EWS like for like is as easy as falling off a log if you have an AK90 or similar tool and are comfortable fiddling. The unknown commodity for me is changing versions of the EWS. Which could also be very straight-forward and I may be raising non-issues. Or my pondering could be correct and it could be tricky.

 

[Southernboy]

Okay, so since the EWS Currently fitted in my car is the one with the apparent software problem, fitting the subsequent upgraded version shouldn't be an issue. However, are you saying that to sync the replacement EWS to my existing DME should be fairly simple using the AK90 tool ?
From what I have read, the EWS also needs to be programmed to the VIN number of my car, and if it is a 2nd hand unit, it will have the VIN # of the car it came from in it's program...??
I have sent Spurs fan / Andy a message asking him if he has a EWS in stock, he will let me know on the weekend. If he does have one, perhaps it might be prudent for me to ask him to send it to you in the first instance. I can provide you my VIN # and you can fiddle about with it using your AK47... .... and take out the old VIN # ??
When looking online at people selling EWS's, there are quite a few that sell the EWS together with the DME and the key with barrel lock and ring antenna... Obviously that would suggest that one needs all these components to be in sync for a straight plug and play fitting.
My conversation with BMW has indicated that they have new EWS's in stock, but I need to take it to them for programming. I wish they would tell me what "programming" is required so I can understand how the system works. Perhaps I should take a drive over to their w/shops and speak to the service manager... maybe he will explain it to me... Worth a try, and that way I can pass on whatever it is he tells me...

 

[Southernboy]

So here is a link to a "geek" forum... their English language usage is somewhat convoluted, and the references in software terminology is Greek to me.... but, they seem to have useful insught into the workings of DME / EWS / ECU programming and tools required.

They appear to be based in the UK... Perhaps you can join the forum and make some sense of their chatter..??

Link:- https://www.digital-kaos.co.uk/foru...ME-and-EWS?s=60f36bf7549cc17c1c1a806d3651f12a

 

[mrscalex]

In the example of a like for like EWS swap.

1. Copy the contents of EWS A to EWS B with AK90
2. Resync (if required) using INPA.

No additional step required for VIN setting.

No DME or locks required. Complete sets are only required for DME swaps. And even that isn’t really necessary since DMEs can be cloned but it’s more complicated.

The complication for you is changing version of EWS. Well maybe it is or maybe it isn’t. That’s the bit I don’t know.

Sorry you’ll have to do the leg work to find out. But happy to verify/interpret any solution.

Btw if you wanted to go a different route you could buy a reprogrammed/hacked DME which no longer goes looking for the EWS. And is also remapped for a couple of extra BHP. But you wouldn’t have an immobiliser any more then.

 

[mrscalex]

I had a quick look at that thread... refer to my earlier messages...

Let me dig something out for you later. There is 1 go to person I’ve found globally for this stuff. A proper expert. You’ll need to join the BMW forum he lives on and PM him. I did that for my sticking relay issue a year ago and he responded very quickly.

I’ll also write the message you need to send him. I don’t want to do the messaging to him for you simply because I’ve got so much on at the moment and I’d end up slowing things down for you by not driving the dialogue with him.

He’ll most likely a) be familiar with the software error (I’ve heard of it myself on reflection) and b) find an easy solution for you.

 

[handsomejackuk]

as @mrscalex as said the immobiliser uses a transponder that uses similar principles as NFC near field communication..

Theres rumours about the key being charged by the ignition ring.

What happens is the transponder ring around the ignition barrel induces a current / voltage in to the transponder chip, there is a small capacitor in there that then turns on the transponder chip and sends the code inductively through the induction ring then onto the ews, then a bit of magic happens with the ews and dme and boom the dme relay I think kicks in and the car will start...

the immobiliser chip has a memory retention of 20 years so theres a lot of immobiliser chip ( transonders) that are getting to the end of their shelf life heres a link to the immobiliser transponder used in some of the cars there are of course clone transponders too

http://www.mouser.com/catalog/specsheets/phlp016.pdf

you can see in there data retention of 20 years

 

[Southernboy]

Thanks!! look forward to the contact info for the "expert"...

 

[handsomejackuk]

No expert by any means.. i just learn off whatever information is available on the internet although i have been in to electronics and computers for about 40 years...

I learn stuff for my benefit and always willing to share my knowledge for free..

my AK90 apparently is in this country so hoping it will be with me in a few days time.. i can get a spare key done for my 2.8 then and sort out my 1.9s immobilser issue...

 

[Southernboy]

So... I've sent a message to mrscalex's expert... Look fwd to seeing what he has to say on the issue too..
I'll post his reply here so any and all can benefit / comment etc...

 

[Southernboy]

How are "files" extracted from the EWS?

 

[mrscalex]

How are "files" extracted from the EWS?

With the AK90 or similar tool.

 

[Southernboy]

PM sent...

 

[handsomejackuk]

How are "files" extracted from the EWS?

can also be done through the k line on the 20 pin diagnostic socket on the car also so i have been informed... just need the right software and a k line interface

 

[Southernboy]

In the past couple of days, the input on this thread has been astounding. I have to say it's been quite amazing how the members involved have collaborated and provided impetus to my query on the EWS question.
The result of all this momentum is that tomorrow I will take my EWS to a local fella who has an AK90, so he can download the files to a memory stick. I will then email those files to Martin, a contact I was given by one of the members in this thread, who is an expert on BMW electronics software. Martin has a spare new version EWS which he will then program with all my car's information and finally, I will have the"new" EWS couriered back to me here in Johannesburg.
This may sound like a convoluted way of getting a new EWS for my car, But cost wise, it's less than half the cost of going to BMW here, and the only other local guy who can do this job, has quoted me the same cost as did BMW,,
I will do my best to gather as much info as I can from Martin and the local guy with the AK90 about the details of this re-programming issue and I'll post it here so that all others have a point of reference which contains no BS or speculative comments. In other words, it can form a sound base to start from where the procedure is clear and unambiguous.

Thank you to all the supporters and contributors - appreciated.

 

[handsomejackuk]

nice one.... let us know how you get on...

my further research has me seeing that one of the problems with the earlier ews 2 systems is that the mcu ( microprocessor contol unit) has an otprom ( one time program read only memory) and the problem with the ak 90+ programmer and some of the earlier programmers I think !!!!!!.. is that the mask ( or otherwise the chip pinout).... can be altered by the ak 90 programmer by choosing the wrong microcontroller and blowing ( resetting all the memory cells ) and making the ews useless... i have some further reseach to do in the next few days, and it looks as though by cutting some of the pins on the ews pcb that this can be avoided...

It looks as though by reading the ews 2 unit with the wrong settings on the ak90+ the data on the ews can be erased...

heres the datasheet from motorola for the mcu used in ews2

https://www.nxp.com/docs/en/data-sheet/MC68HC11EA9TS.pdf

maybe someone else that has read an ews2 can confirm this ?

consequently later ews units.. have a different mcu that has an eeprom ( electrically erasable program read only memory) and not an otprom and this issue has been fixed so a later ews would seem the way to go if you need to get extra keys programmed... things have moved on a lot since 1995 - 1998 in the world of microcontrollers...

or just get a ews delete or do as others have done the old trick...!!!!!!

 

[handsomejackuk]

the key to it is to look at the processor mask code on the processor...in the ews...

1d47j, od46j etc.. let me know if i am wrong @Southernboy as you are taking your ews to someone who is going to potentially READ your ews.... you wouldnt want that data to be lost just by reading it...!!!!

i just hope he knows what he is doing as i have not attempted reading the data myself yet....

i think i need to get a spare ews before i commit to reading the one off a running car.......