Hi all,

Recently got a key fob off ebay for my Octavia (flick-out style).

I have followed the instructions on Ross-tech for key matching for IMMO3 and also checked out the Measuring blocks for IMMO3 document.

My problem is this...

...with the new [un-matched] key in the ignition I get this...

Block 22 0 1 1 2 (all OK, legitimate transponder)

Block 23 0 1 0 6 (variable code not matched (expected) / Transponder in key is locked / Fixed transponder code of key is not authorised / immobiliser operating normally)

With original [working key] key I get...

Block 22 1 1 1 2

block 23 1 1 1 6 (Transponder is locked and Fixed transponder code of key is authorised)

I am guessing I have been fobbed-off ('scuse the pun) with a duff key fob, perhaps cos it's been programmed to another car. Is this the case?

Can someone please explain this in some detail regarding the fixed codes and transponder locking? I realise the key fob may be useless but even so I need to understand what to look for if I find another on the cheap.

Does anyone have a source for cheapish key fobs?

Good news is that recoding my old key back went great so I can still drive my car!!

Your car wont be immobilizer 3, but anyhow have you tried programming the key?

When you say fob do you mean the remote or the transponder?

Coding is quite simple but you will need to do both keys.

17 - dash insert

11 - login

Enter your four pin code for the immobiliser

10 - adaption

Channel 21

Enter number of keys to program (i.e 2)

The turn the key off and remove, enter the next key and turn the ignition on. Both keys will no be programmed.

Coding the remote is a different procedure.

Im not sure how you would code the transponder to another car as the key will be cut to your vehicle.

Sorry Lummox,

Just read my post and realised how misleading it was using the word fob. I am actually referring to the key and transponder part, I have not tried programming the "fob" for the central locking yet.

I believe I have immo 3 as the notes on Ross-tech point toward having it, namely, my instrument panel in VAG-COM has both VIN No and IMMO Number displayed.

I tried to match the keys to the immo exactly as you have suggested but upon inserting the 2nd key (the 'new' one) the immo light on the dashboard just kept on flashing, indicating an error and the 2nd key didn't work.

I suspect the above differences in the measuring block values (after referring to Ross-tech's pfd on immo3 Measuring Blocks) are the reason that the new key doen't work.

Perhaps as you said, it has been previously matched to another vehicle and there is no way of changing that, so effectively the transponder code is write once.

I really just wanted to understand for sure, as it was advertised as brand new and if it has previously been matched to another car then it is not brand new and I have good reason to complain to the seller.

By the way, matching my original key after the above failed attempt was easy so I am following the procedure correctly.

If all else fails I'll just transplant my tatty old key into a shiny new case, not so much of a waste then! :P

You can code a transponder as many times as you like to as many vehicles as you see fit.

Your immobilizer is 2.5, it has chassis details but uses a four pin code. Immo 3 uses the seven digit coding. However there are different types of transponder in the key, maybe you have a different sort. Should have a W on the key shaft.

For clarification reasons...

1. There is no IMMO-2.5
   
2. To determine which IMMO generation you have to check if the cluster/ecu stores IMMO-ID AND VIN (that's IMMO-3) or just the IMMO-ID (that's IMMO-2).
   
3. 4-digit SKC's and 7-digit SKC's are the same, a 7-digit SKC is a crypted version of the 4-digit SKC, even if you enter a 7-digit SKC into the diagnostic tool, the code transferred to the control module is actually te 4-digit which is beeing automatically "decrypted" by VAG-COM.
   
4. IMMO-3 transponders which are locked can only be matched to the IMMO-ID they are locked on.
   
5. The W on the key blade represents "Wechselcode" which is the german word for "variable code", which would be either IMMO-2 or IMMO-3.
   
6. Based on the fact that your MVB 023 field 4 shows a value (in this case 6), you should have IMMO-3.
   

There is no IMMO-2.5

OK, i'll let VAG know the manual is wrong.

Fabia doesnt list a Immobiliser 3 in the workshop manuals. Only immobilizer 2. But it still has immobiliser coding in the engine ECU. We gernally call this 2.5 as it has parts of both.

Fabia doesnt list a Immobiliser 3 in the workshop manuals. Only immobilizer 2. But it still has immobiliser coding in the engine ECU. We gernally call this 2.5 as it has parts of both.

Let's talk about some real data from a 2005 Skoda Fabia.

Address 01: Engine
  Part No: 036 906 034 HG
  Component:  MARELLI 4TV        6295
  Coding: 00073
  Shop #: WSC 13765
  TMBMC26Y754219375     SKZ7Z0D2673485

Address 17: Instruments
  Part No: 6Y0 920 891 L
  Component: KOMBI+WEGFAHRSP VDO V02
  Coding: 28101
  Shop #: WSC 13765
  TMBMC26Y754219375     SKZ7Z0D2673485

The definition of IMMO-3 is that it stores VIN and IMMO-ID, which is the case in the above scan - I also have other scans with the same content from 2000 to 2006 models. Skoda Fabio (6Y) and VW Polo (9N) have always been IMMO-3, from SOP (Start of Production) on.

Not the first time a manual isn't 100% right.

Not the first time a manual isn't 100% right.

Oh I would agree with that no problems. When it comes to Fabias and dash inserts and programming then anything goes sometimes.

Regardless of our little side debate here It sounds like this chap is doing it right, its just for some reason the second key will not code. This could be down to a faulty transponder or and incorrect transponder. If the login code was incorrect it would chuck you our straight away. An easy way to check a login security code is to try the same login procedure in Engine 01. If it accepts it then its fine.

For clarification reasons...

1. IMMO-3 transponders which are locked can only be matched to the IMMO-ID they are locked on.
   

Which means' date=' if you buy a used IMMO-3 key/transponder which is locked, you can't code it to another car - [i']normal[/i] behavior.

FABIA???

I drive an Octavia, or were you using Fabia as an example of a very similar car?

Anyway, thanks for your replies and the friendly debate, quite entertaining!

Just to re-affirm I have both VIN and IMMO number so I must have IMMO 3, besides the IMMO 3 key-matching procedure worked, just not on the new key (re-matched my old one after the C**K-UP with no problems.

The four digit code worked (proven by the above procedure working). The only letters I can see on the key shaft are FAB. Definately no W :( . Can the W be joined by other letters or will it be on its own?

Does anyone know of a reliable source for this type of flip key (and not the stealers!), specifically keys with the variable code.

I have been reading up and there is some reasonably priced equipment available to code keys for just about any car you can think of, I can feel a possible business idea brewing...

Do general posts in this forum show much of a demand for keys at reasonable prices? As you're the guys that answer all the questions I guess you would be the best to ask.

Thanks again

By the way where did the name BRISKODA come from (the BRI bit not the SKODA bit!) Does it simply stand for Britain?

VAG COM is all you need to code keys once you have the code on VAG cars but im not sure about any other make. MAybe you are refering to the copiers you see in key cutting places?

And as for what Briskoda means, try reading under the main title up the top /\

FABIA???

Sorry, was referring to Lummox statement which was about the Fabia.

Just to re-affirm I have both VIN and IMMO number so I must have IMMO 3, besides the IMMO 3 key-matching procedure worked, just not on the new key.

Correct, that's because the transponder is already locked.

Can the W be joined by other letters or will it be on its own?

Would be on it's own - don't worry about it not beeing there.

Does anyone know of a reliable source for this type of flip key (and not the stealers!), specifically keys with the variable code.

Well, best way would be to get just the transponder but they are usually not sold seperately.

Do general posts in this forum show much of a demand for keys at reasonable prices?

I'm quite active in several forums and requests like that are pretty rare, point here is you can easily get used keys and new (uncut) key blades, what you usually can't get are IMMO-3 transponders.

I have seen transponders with blank keys for sale elsewhere on the web that look compatible, will have to find out if they are IMMO 3 compatible.

Cheers Guys:cool:

I have seen transponders with blank keys for sale elsewhere on the web that look compatible' date=' will have to find out if they are IMMO 3 compatible.

Cheers Guys:cool:[/quote']

You can buy just the transponder on it's own. They list fixed and variable transponder types.

Can you give me the part number inside your working key?

You can buy just the transponder on it's own. They list fixed and variable transponder types.

That would be new. Which of the numbers in the pictures "should" be the transponder?

33 = Battery

34 = Light Bulb

35 = Battery

39 = Battery

VRStu, wWhen you say 'they' do you mean the main dealer or another company?

Part No is: HLO 1J0 959 753 AG (Looks like transponder No. 38 in your pic)

and it's 434MHz

Part No is: HLO 1J0 959 753 AG (Looks like transponder No. 38 in your pic)

and it's 434MHz

STOP! Transponder means in this case "rear" part of the key. Remember a switch blade key like this actually consists of 2 parts' date=' the front which has the blade and the immobilizer transponder and the rear which has the remote buttons and the remote battery. The part number 1J0 959 753 AG stands for a rear 2-button remote part like shown in the following picture.

[img']http://eleanor.tool-base.de/tuning/klappsch/sender_2tast.jpg[/img]

Yes, I realise that. Bad phrasing again I think. I meant to say that the part number is HLO 1J0 959753 AG (the remote) and the transponder unit (with the key attached) looks like No 38 in the pic. I wasn't referring to the remote as the transponder.

Did you want the part mumber off the transponder unit itself? I guess I would have to open the transponder up as there are no numbers on the outside.

I do have the original tag that came with the original keys (barcode tag) and it has the remote part no printed on it. Do you think it may also tell me what transponder is attached to the remote?

Ta,

Steve

Actually Stu was the one who wanted the numbers, personally I don't know a VW/Skoda part number which would let you order an immobilizer transponder. In theory you could read the number off the immo transponder itself, but that would require opening the front blade part of the key. There are 2 versions of immo transponders used, ceramic ones and glass ones - according to my experience it is nearly impossible to get the glass one out of the key without either destroying the transponder or the key, the ceramic ones are easier but usually require a lot of patience to get them out.

Finally what you would be able to read is a Phillips number which you can use to order, not exactly sure what the number is but saw it recently somewhere. There is one german company that sells these, but they want 25 EUR each, and a new key front costs 40 EUR, so not much money saved and 15 EUR are IMHO not worth the hassle. I'm sure there is a cheaper source, one just needs to find it.

Sorry about the mix-up, so many people in the discussion I got a bit lost with who was who!

The link below is for a UK site that seems to supply a wide range of transponders, keys and remotes.

There are two transponder (chips) listed for the VAG group and there are a number of 'key fronts' with the blank blade and transponder. Very little info on each though, it's a bit unclear exactly which supports which.

http://shop.advanced-keys.co.uk/

Will make enquiries as to which is suitable for mine, not sure if they may need programming/coding using their software first or if they are simply ready to pair with an IMMO.

Item 38 for a folding key. Around £45 plus VAT.

As I said depends on the part number of the current one.

If yours is no 38 then it may be -

3U0 837 246 B INB

Main key with variable code transponder (folding key). For models with radio remote control central locking system. 11/02 onwards

Sorry about the mix-up' date=' so many people in the discussion I got a bit lost with who was who!

The link below is for a UK site that seems to supply a wide range of transponders, keys and remotes.

There are two transponder (chips) listed for the VAG group and there are a number of 'key fronts' with the blank blade and transponder. Very little info on each though, it's a bit unclear exactly which supports which.

http://shop.advanced-keys.co.uk/

Will make enquiries as to which is suitable for mine, not sure if they may need programming/coding using their software first or if they are simply ready to pair with an IMMO.

I would say you are maybe getting a little involved there mate. That looks like a solder on chip to repair damaged ones.

As I posted above you can quite easily buy the transponders you just need to be sure which one you need and that is easily acheived checking part numbers.

Thanks for the info VRStu

Regarding the transponder, I know little about them in the car keys but we do have them in work in door access tags. The tags are simply a small graphite-looking disc. They are programmed using no connectors similar to matching car keys to the IMMO.

As such I believe the transonders are self-contained (as they also need no external power supply) so they may just drop into the transponder case with no further work required. Not sure though, I may open my duff one up to find out!!!

Cheers again

As mentioned before here are terms beeing mixed, the immobilizer transponder is as alrady stated a small glass/ceramic unit which is part of the front key blade part of the flip key. These transponders are beeing programmed through the immobilizer reading/writing coil using electro magnetics, there is no power supply needed for these transponders, the electro magnetism does that job.

So what/who is mixed-up?

I agree with what you have said but it's just slightly different wording to what we have been saying all along isn't it?

Remote unit with battery attaches to transponder/key unit with no battery. Together they make what we often just refer to ask car keys....as in.... honey, where the F**K did you put my car keys!*@!??

Steve