Replacement key.....

[Buttons76]

Sure its been asked a thousand times before but i cant find a concrete answer to my question!
I bought an E46 yesterday for a cheap, daily, runaround.

Thing is, ive only got 1 key for it and I like to have a spare.....
Ive read about the shocking prices that stealers quote for a second key but i dont care about remote locking, i'll use the door key lock like old times!
Thing is; can i simply get a new key cut that will open the doors and start the car or do i need to go down the coded key route (I really dont want to do that!)

[d_a_n1979]

IIRC a cut key will open the doors, but it won't start the engine; for that you do need to get it coded

[Collectingbrass]

In 2019 I got a key from BMW for a 2004 Z4 and it was £150 coded & set up by the techs at the dealer. Mind you, that said, I ran a shed of an E39 for two years with one key, I was just very very careful and had lost key insurance.

[p4cks]

I've always enjoyed the insurance of a second key, but I can count on the hands of a double amputee how many times I've needed it

[to3m]

d_a_n1979 said:

IIRC a cut key will open the doors, but it won't start the engine; for that you do need to get it coded

Mine had a tiny plastic emergency key that would do both, suggesting that you might just need a key that's got the right pattern? I also had no problem getting into my car using a keyfob with a dead battery.

I don't think you can activate the alarm without a working fob though.

(From memory, if you use such a key to open an alarmed car, the alarm goes off - you have to turn the key in the ignition a couple of times to make it stop.)

[bearman68]

OP, there's a degree of misinformation on this post already.
The E46 has a coded key. It's not particularly easy to code, but it can be done by most competent auto locksmiths. There is a small box in the dashboard that is usually removed, and the key coded directly to that. I forget what it's called on a Friday night after red wine.

The key cannot be copied because it has a rolling code.
The key has to be coded to the car for the immobilisation to be deactivated.

It's nothing like later versions of BMW keys, and is akin to the E39.

A key should cost you about £150 or so, with the majority of that cost associated with the coding, and another £20 or £30 for a remote key.
BMW are unusually cheap for keys - the main dealer may be as cheap as an auto locksmith.

(I make and programme keys as part of my auto electrician business)

[Mr Tidy]

I think new keys need to be coded to the gm5 module.

I bought an E46 Compact in 2014 and somehow managed to lock the key in the boot! That's when I discovered the spare key had only been cut not coded but as I was at home only the neighbours were upset until I could turn the alarm off!

So when I bought an E86 (Z4 Coupe) in 2016 that only had one key I managed to find someone in Cheshire who cut and coded a flip-style key for me and deleted the missing keys for £80. If you are in that part of the world search for "ZedShed Cheshire" and you'll find him on FB.

I've also read good things about "bmkeys" in East London (also on FB) but I'm sure there will be others.

[ian332isport]

E46 era BMWs use a system called EWS3. When the car is built, 10 transponder chips are coded to the EWS (immobiliser) module. I believe 3 or 4 of these transponder chips are delivered with the car in the various keys it’s supplied with. BMW hold the balance for replacement keys.

When you order a new key, it will use one of the remaining transponder chips. You don’t need to code these to the car. If the new key has a remote for the central locking/alarm, you need to pair it with the car, but it’s a diy job.

Once all 10 transponder chips are used up, you need to buy a replacement EWS module that has 10 new transponder chips coded to it.

That’s the official line. I believe aftermarket kit is available to code new chips into an EWS module. It’s not something BMW can do though. They can disable lost keys though.

[Matt_E_Mulsion]

I have no idea what model of BMW an E46 is, but most car keys can be cut and programmed by decent auto locksmiths. I believe that this is achieved by making a clone of the working key that you already have. The car will not be able to tell the keys apart and work with either, where as an original key from BMW would be uniquely identifiable to the cars 'brain'.

Here in the Midlands I would expect to pay somewhere in the region of £250+vat, dependant on the style of BMW key at an auto locksmiths.

[rfsteel]

I paid £124.75 + VAT and coding a couple of years ago for a BMW replacement key (PN 66 12 6 933 727) for my MY2002 E39 via my specialist.

If you just want a spare key for the door locks, then getting just a blade or valet key cut will be the cheapest option;

https://www.ebay.co.uk/itm/154047385838

or possibly your local Timpson's might be able to help;

https://www.timpson.co.uk/services/car-keys

[bearman68]

Matt_E_Mulsion said:

I believe that this is achieved by making a clone of the working key that you already have.

.

No, that's not correct for the BMW, as the code changes every time you use it. (rolling code). Copying the code will not work because that code has already been used.

As auto electricians, we would remove the EWS, and programme directly to the EWS. It's not the easiest job in the entire world, but can be done.

But it might be as cheap to have a key from BMW - the chap above who says there are 10 key codes is prob not far off, as there are about 10 (maybe 8) slots in the EWS for different number keys.

[ian332isport]

Full details here.

https://www.meeknet.co.uk/e38/E38_Immobiliser_Syst...