E39 Master Key Options

[GotBeef]

I called my local dealer and a replacement master key will cost $240. My research tells me there is no alternative for a master key aside from the dealership. What did you pay for your replacement master key?

And could I buy this key:

http://parts.bmwofbridgewater.com/p/...218374066.html

and then program it to my car? Or is strictly the key with battery and no chips?

Thank you. Your input is greatly appreciated.

[djb2]

No, you won't be able to program that key to your car.

Your options are to buy a pre-cut, pre-coded key from BMW ($60-260), or cut and code an aftermarket key.

If you buy a key with a remote locking transmitter, you'll need to initialize the remote locking. That's a trivial operation that's the same for both, so we can skip the description. This is *not* 'coding' or 'programming' - it's just configuring the remote locking receiver.

To make your own key requires a key-cutting mill ($150-$1K for the machine, or $20-$40 to a local locksmith) and an EWS programmer ($50-$500, with few locksmiths having one).

A reasonable compromise is buying a new blank diamond key for $30-ish from FleaBay, finding a locksmith that will copy an existing key for $20-ish. Once you verify that the key will physically unlock the car, and can remote-unlock, buy the programmer. An AK90 EWS programmer will cost $50-$90 and isn't that difficult to operate if you have a Windows machine.

The EWS programmer requires removing and opening the EWS module. After cleaning any coating from the main chip's pins, you press on a special programming harness (really a PLCC socket used upside-down) and read the pre-programmed key codes. From this you can program the transponder on a virgin key with one of the unused codes (preferably #10, the last entry).

I bought both a key cutting machine and an AK90 to make my keys. But that's because I'm a .. uhmm.. hobbyist. Most people are probably better off borrowing an AK90 and having a locksmith cut the key.

[Dking078]

I would try and get the dealer to price match, that's what I've done.

I was able to get away with $180 Out the door and that was down from $260 + tax all because I showed them I could get it cheaper from another dealer (A bit of a long drive though). The only difference being the other dealer operated online orders only.


Are you looking for just an extra key or buying due to a dead battery? (Pre-9/99 should be able to replace the battery IIRC)

[RocketSurgeon]

I bought all the high dollar gear to cut and program my own. I've cut a few for my neighbors too. Be careful what blanks you get, a bunch of them are sketchy. Either the key blade is something other than brass and it trashes the cutter, or the transponder is used or the wrong type. My neighbor even had one where the blade was way out of spec. BTW the 4 track key is much harder to cut than the 2 track, it needs to be within 0.07mm or so, which is beyond the scope of the cheaper cutters.

[edjack]

How do you source and program the RFID chip?

[RocketSurgeon]

How do you source and program the RFID chip?

My supplier includes PCF7935AS transponders with the blanks that I order. I could of course source the transponders elsewhere if necessary. I worked out a specific combination of key blank, remote, and transponder that seems to be the best match. The winning combination is a brass blade on a case with appealing markings on the back (no Mandarin) that will accept a roundel, the PCF7935AS transponder, and a remote with replaceable battery. To program the transponder I use a programmer similar to the ak90 with extra features for other makes. I extract the EWS bin file and write a fresh transponder to an available slot. Sourcing good parts seems to be the real challenge, the US sellers have keys with used 10030a transponders that can't be rewritten and won't accept a roundel, and the Taiwanese seller lies about his "refurbished" keys, and one of the Chinese sellers supplied incompatible transponders that the car can't read. The only viable option is really the PCF7935AS

[cnn]

Master key w/o remote feature is $50. Search forum for QSilver7's posts.

[djb2]

I bought all the high dollar gear to cut and program my own. I've cut a few for my neighbors too. Be careful what blanks you get, a bunch of them are sketchy. Either the key blade is something other than brass and it trashes the cutter, or the transponder is used or the wrong type. My neighbor even had one where the blade was way out of spec. BTW the 4 track key is much harder to cut than the 2 track, it needs to be within 0.07mm or so, which is beyond the scope of the cheaper cutters.

The 'high dollar gear' takes a picture of a key, decodes the key cuts, and uses a CNC router to cut a precise profile.
The low end equipment traces the outline of a worn key. Even the $150 machines can do a pretty good job if you spend an hour to align the clamps and use the proper shims under the key.

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The winning combination is a brass blade on a case with appealing markings on the back (no Mandarin) that will accept a roundel, the PCF7935AS transponder, and a remote with replaceable battery. To program the transponder I use a programmer similar to the ak90 with extra features for other makes. I extract the EWS bin file and write a fresh transponder to an available slot. Sourcing good parts seems to be the real challenge, the US sellers have keys with used 10030a transponders that can't be rewritten and won't accept a roundel, and the Taiwanese seller lies about his "refurbished" keys, and one of the Chinese sellers supplied incompatible transponders that the car can't read. The only viable option is really the PCF7935AS

I buy 10 packs of the 7935 transponders. They are much less expensive than singles, and 50 packs aren't much less expensive.

You want cupro-nickel blades, not brass. Brass is softer and easier to cut. But it's a foolish economy. Putting $0.25 of wear on a cutter (probably more like $0.10) is a big deal for a store selling common keys for $0.89. But when you are cutting a key that costs $30, you don't want the blade to bend or wear out in a few months.

I don't think that steel is an option. Older BMWs used steel (stainless steel) keys from the factory, with aftermarket blanks being brass. Factory keys lasted much longer than brass copies, and were much less likely to bend or break off in the lock. You could buy uncut factory keys, but the stainless steel would *really* wear a typical key cutter.

It's possible to reprogram some of the transponders, therefore theoretically possible to have a "refurbished" key. But to rewrite you need the cryptokey read from the original EWS unit. And I'm 99% certain that no one-off FleasBay seller is doing that.

[geargrinder]

The 'high dollar gear' takes a picture of a key, decodes the key cuts, and uses a CNC router to cut a precise profile.

Yeah. My key guy has the gear where there's no tracing - read the key and create a digitized key code, not a trace. Means that - immobilizer aside - you can show up without the car and get him to rip a key. I brought him some quality Huf blanks I got on eBay and he was impressed - told me most people bring him crap that he refuses to use.

Unfortunately he has 2 locations and I went to his retail shop in a mall the other day to get a Merc key done and the punk idiot kids he has working there did not make nearly as nice a key as he makes. His "copies" are way sharper than the worn out key, they gave me a crap trace copy and charged me the full boat for it. Gotta figure out what his hours are at his 'good' shop and never go to his idiot mall shop again.

[edjack]

Wow! Lots of information! Thanks.

[RocketSurgeon]

You want cupro-nickel blades, not brass. Brass is softer and easier to cut. But it's a foolish economy.

You're right, they are cupro-nickel and not brass. My supplier was incorrectly using the word brass for "copper-alloy." I tested with hydrochloric acid and the blanks don't contain any zinc. One of my neighbors brought me a key that was extremely hard to cut, the point is not all of the blanks are made of the right metal.
As far as the $150 machine goes, I've been down that road. Shims and careful alignment will allow you to cut a 2 track key, but the 4 track won't cut right. The manufacturer even admits that the tolerances on that machine aren't tight enough for the HU58. Perhaps some will work on the HU58, but upgraded machines have closer tolerances and cut better when I measured the resulting keys with calipers.