Key Broke - Car wont start - EWS??

[MisterM52]

My recently purchased Z4 (E85 2003 3L Manual) came only with 1 key, and its not even the original.

While I was working on my car the other day, my key was still in the trunk lock and I accidentally hit it on my way walking around it and the whole key fell apart. Only damage I see is the plastic tab holding the metal key itself had broke, the chip inside and such is all fine.

So I put it back together and now the car wont start. What are my options?

I thought about maybe its the EWS and I need to do an EWS delete. Any resources will be highly appreciated.



Note: I also had my GM5 Module recently fixed (sent it in a local repair shop who does them, and they repaired the GM5 Module with those new relays. All works, however I am trying to figure out whats the deal with the key.

 

[PDJ]

You can have BMW make a key from the VIN number about £140ish

You sort of need one good one anyway and rules out other issues

It could be the EWS and the other electronic unit has lost coms

 

[MisterM52]

So far, did a lot of digging and plan to do more later on.

I had disconnected the battery as I was doing some work. Could that be related? I was not aware the battery on a 2003 model needed coding?

It seems to point to the EWS having lost sync with the Key itself. Although I was able to program the key to open and close the central locking and such. Wonder if I can reset it with INPA or such?

 

[colb]

Sounds like you have lost the small black transponder from inside the fob when it fell apart. You may be lucky and find it if you do a search of the ground where it happened. If you do find the transponder put it back inside the fob and if you can still use the blade in the ignition the car will read the transponder and allow the car to be started.
The pcb inside the fob is only for the central locking functions, the separate transponder chip is the other part it is not powered by the pcb battery it just has to be present inside the fob.

 

[MisterM52]

Hey Colb,

Small black transponder? I may be able to have a look at the floor. Do you have a image or such that correlates or gives me an idea so that I can have a look? I was under the impression anything important is soldered to the pcb.

Alright, So, I am thinking if I should then buy a blank key and swap the cut part and leave the transponder and all such inside, then get myself an AK90 Key programmer that can read the key codes from the EWS Module and can write to the new key?

Found this video that explained it well.
https://youtu.be/lKUO-W8E8j4?si=lXtYk6JWosBYPEE3


All tips appreciated.

 

[MisterM52]

I did some google, so would this small black rectangular piece shown on this picture (to the very left of the diamond / keys happen to be) the transponder? It just stays inside these blank keys? Interesting.



Now if I have absolutely lost the transponder, what should I do? What are my options? I see no other way but to buy the AK90 and buy a blank key or so.

Could I just buy a transponder chip and program it and put it inside the key, any chip specs or links I can get it?

 

[PDJ]

Now if I have absolutely lost the transponder, what should I do? What are my options? I see no other way but to buy the AK90 and buy a blank key or so.

BMW will make one from your VIN number

 

[DMike]

Now if I have absolutely lost the transponder, what should I do? What are my options? I see no other way but to buy the AK90 and buy a blank key or so.

BMW will make one from your VIN number

And that will propably be the most cost efficient way saving time and trouble. Several earlier threads on the subject.

 

[MisterM52]

Alright so I have figured it all out.

The Transponder in the chip was found and I fixed the key and it started right up!

The parts / notice the transponder (small dark / black rectangular chip with a corner cut at an angle). If there is no crank, means its the link between the EWS and the KEY. Which was my case as the Transponder went missing.



The metal key itself had this portion broken right off the plastic, I used a heavy duty soldering iron with plastic welding tips.

Then I sent and cut the nail to size with an angle grinder and melted the nail deep in there to hold the key.



and then added the key itself some more plastic melting and welding, and then epoxy and clean up later, voila, a fully functioning key.





I will also go and buy 2 more blank keys, have them cut and I will program them myself.

 

[colb]

Ebay Chinese keys come with the transponder and the pcb the transponder will have to be coded to the EWS system in the car to allow it to start. The central locking functions have to be programmed using the finger dance methods on the fob buttons, instructions to do this on old posts on here. If your going to try an AK90 machine, best of luck, I tried but couldn't get a key coded using it. I glue the transponder inside the fob so it won't fall out if the key gets dropped and breaks open.