E39 Key

[bimmer boy 21]

So as most of you know I have a '97 E39 5-Series and the other day I was on the internet and found a website for car keys so I thought I should buy a few and get them cut and kept as spares.

I got the keys mostly just to keep at home so if I locked my keys in the car I got another set to be able to get into the car in this event. I am well aware that in order for a key to start the car it must be programed and chipped paired to the car.

So I got a key exactly like the diamond shape BMW keys. I was reminded when I got them cut that they wont start the car as the key was most likely for people to swap over the insides of my existing key into.

I got them cut and was on my way and I got home before and just out of curiousity I tried to start the car with the keys I just got cut and what do ya know, they started the car.

So I thought maybe it was because my chipped key was right next to it so I took it off my key ring and put it inside the house and still the car starts...

Now I am thinking my car can start without needing to be chipped, or is there something wrong with the EWS or what ever?

[matt45 1]

have often wondered this with the plastic wallet keys, are they just plastic or is there a passive chip in them?

[bimmer boy 21]

have often wondered this with the plastic wallet keys, are they just plastic or is there a passive chip in them?

I always thought the plastic wallet key was just a key you use so you can get into the car but not actually drive it?

[Smac01 12]

How much did it cost if you don't mind me asking?

[matt45 1]

I always thought the plastic wallet key was just a key you use so you can get into the car but not actually drive it?

95% sure i've driven with it before

[hybrid 1043]

The key is coded to your EWS module and when inserted into the key is in range of the reader coil tells the EWS module that a key (transponder chip) is present then sends its coded message to the DME. The DME is then coded to your EWS module and when all three match the DME will allow the car to start. (Fire the starter relay/circuit.

When your chip is not present however your lock barrel is unlocked and starter fired the DME will allow the car to fire for a split second then kill the ignition.

This wont allow anyone to just drive the car away however it allows you to tell that there is nothing wrong with your engine/starter system etc.

I would say that one of two things has happened. Your EWS read has been disabled on the DME. Or the reader coil is still reading your key some how.

[bimmer boy 21]

Thanks Josh, good information!

Yeah I have driven the car with the new key but I had the other key hanging next to it but I had the other key in my room and I backed the car out of the driveway before with the new key and went fine. Tomorrow I'll take it for a drive just with the new key and see what happens. I would prob say something has been disabled which is kinda weird but I guess isnt much of an issue..

[bimmer boy 21]

How much did it cost if you don't mind me asking?

The key itself was some rediculously cheap price like $6 US and then $24 to have it laser cut...

It is exactly the same as this or like any other diamond shape BMW key only it is empty inside.

Edited May 17, 2011 by RJS

[hotwire 352]

Don't know as I haven't tried on the BMW's but... maybe immobilisation activates after a time frame (some cars do) - eg - after it has gone to sleep & woken

[bimmer boy 21]

Its pretty strange. I will try it again in a minute when I leave to go do a few things. I think I will keep the other key in my wallet just in case though.. Im pretty sure I wont have any problems though but we'll see. Perhaps it might be time to get an alarm anyway...

[M5V8 337]

i'd been keen on one of those keys if you have a spare or could get more? Do you know how to get the insides so they work properly

Edited May 17, 2011 by M5V8

[matt45 1]

i'd been keen on one of those keys if you have a spare or could get more? Do you know how to get the insides so they work properly

http://s.dealextreme.com/search/%2bbmw+%2bkey

[bimmer boy 21]

http://s.dealextreme.com/search/%2bbmw+%2bkey

Yep thats the site I got them from. I mean they are so cheap and free shipping so why not? I've just ordered a few for Mums and my sisters BMW's, just as a spare to get into the car they are great and in my case they are super great since I can now confirm I can drive my car around with the new key.

As for the insides I would say they are only any good if your old key blade or casing is buggered and just swap the insides from the old key into the new casing..

[Yankus 0]

Have you tried locking the car with your old key, taking it well away from the vehicle, wait 20 mins and then trying the new key to see what happens?

[hybrid 1043]

Don't know as I haven't tried on the BMW's but... maybe immobilisation activates after a time frame (some cars do) - eg - after it has gone to sleep & woken

If either the Key/Chip or EWS module are not present the DME will not start.

If the Key is not present and the EWS module is, it will fire for a split second then die.

If RJS opened his car I would think someones done something dodgy and tied the old chip and reader coil together and replaced the ingnition barrel with another lock and that key isnt even part of the EWS. Thus the key is only mechanical.

I forget where the EWS module is on a 5 series (think its over the glove box side) .. follow the wires and see if the reader coil is even plugged into the ignition barrel reader coil.

The chips are tiny ... about half a finger nail in size. ..

Mechanically your key is doing its job, but I think your EWS has been played with. (Common in import cars or stolen recovereds where they key has been misplaced)

Happy to scan it for you if you like to check for DPS codes

[*Glenn* 854]

I've seen this happen before.... disconnect the battery for half an hour and then try the non gen key... should not work unless something has been done as Josh suggested

[bimmer boy 21]

Have you tried locking the car with your old key, taking it well away from the vehicle, wait 20 mins and then trying the new key to see what happens?

I might give this a go now... Stay tuned

If either the Key/Chip or EWS module are not present the DME will not start.

If the Key is not present and the EWS module is, it will fire for a split second then die.

If RJS opened his car I would think someones done something dodgy and tied the old chip and reader coil together and replaced the ingnition barrel with another lock and that key isnt even part of the EWS. Thus the key is only mechanical.

I forget where the EWS module is on a 5 series (think its over the glove box side) .. follow the wires and see if the reader coil is even plugged into the ignition barrel reader coil.

The chips are tiny ... about half a finger nail in size. ..

Mechanically your key is doing its job, but I think your EWS has been played with. (Common in import cars or stolen recovereds where they key has been misplaced)

Happy to scan it for you if you like to check for DPS codes

Yeah I am begining to think it maybe have been played with by a previous owner or what ever, I was looking through old history I have of the car I wouldnt be suprised if it was a stolen and recovered car.

I dont think it bothers me at all because if someone wants to steal my car they will do it one way or another so im not concerned at all was more curious as to how a non chipped key could have started it... Very strange

[bimmer boy 21]

I've seen this happen before.... disconnect the battery for half an hour and then try the non gen key... should not work unless something has been done as Josh suggested

I will give this a go also, thanks Glenn

[bimmer boy 21]

I gave the disconnecting the batter a go with the gen key inside in my room and the new key still started it and I ran it for a few mins to make sure. So I guess someone has had a play with my car at some point, no biggy. Alarm time then...

[joshnz 2]

I already have an alarm system installed on my car, I assume it is possible to transfer the internals of my key pictured below into a diamond key? Not for the button functionality just for EWS chip purposes?

Anyone know how big the chip is inside my key without me ripping it apart?

[JFry 1]

Its quite small:

[joshnz 2]

Legend, cheers mate, my Google skills fail.