p38 key fob again

dogsbody said:

Mozz,
I know that's normally the way to go if you've got one working key so don't want to duplicate it when you buy a new one. But if he's only got one key and he's replacing that one and getting a spare why shouldn't he get other numbers. If he's got memory functions isn't key 4 the one that doesn't operate these?

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yea but the car will already have a key 1 and 2 programed in and that would need removing from the memory before it would acept another on the same number so better to get a key its never had before

hi dogs , key 1 and 2 are standard supply with new vechile!!!!!! there is 4 keys available as a master supply ,as I said 1 & 2 issued at new . if a customer replaces one of them but due to loss of number i.e. on white sticker on fob then owner or dealer cant identify which is wich , as usual with all keys when stickers fall off or unreadable !!!! so as an interim most dealers would re order key 3 !!!!!! but due to cars being sold numerous times over a period theres no way of being sure if key 3 has been issued except by the manufacturer HUFF in Germany as where they are put together after computer has done its bit on the innards i.e. printed circuit .. so most u.k. dealers worth their salt would suggest that key 4 should be ordered because say key 2 was ordered then im told reliable source that it wouldn't work ?????????? don't ask me why .its beyond me that one is !!!!!! they say that if you order wrong key against their suggestion and its paid and delivered and doesn't work then they wouldn't accept responsibility and you would have to pay agsain ?????? and at 120 quid a throw its a joke !!!!!!! so moral of story follow their advice and order and pay for key 4 as per their instruction and if by chance its doesent work ,then its dealers cock up and their responseability !!!!! does this sound understandable ??????????? cheers mozz

p.s. all 4 keys are programmed and coded individually at huff !!!!!!

gfromleeds said:

yea but the car will already have a key 1 and 2 programed in and that would need removing from the memory before it would acept another on the same number so better to get a key its never had before

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Wrong, you can replace 1 or 2, you just cannot have 2 with the same number in use at the same time.

datatek said:

wrong, you can replace 1 or 2, you just cannot have 2 with the same number in use at the same time.

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+1:d

Datatek said:

Wrong, you can replace 1 or 2, you just cannot have 2 with the same number in use at the same time.

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+1 aswell.

If you have memory seats on the drivers side, you can find out if you have Key 1 or Key 2 if the sticker has gone (like in my case)

Save memory preset 1 at one extreme of the seat travel
Save memory preset 2 at the other extreme of seat travel
Set seat in middle of travel
Superlock the vehicle

On unlocking 'Lazy Unlock' (Press and hold the unlock button on the remote, or turn and hold the key in the door to the unlock position)

The seat will move to whatever preset the key is (memory 1 for key 1, memory 2 for key 2)

If the seat doesn't move, then either the vehicle wasn't superlocked, or your lazy unlocking didn't work... or you have a Key 3 or Key 4.


Worked for me, as I said - I found out I have Key 2 - so will re-order another Key 1 at some point...

Here's another question though for those 'in the know' about BECM's an keys...

Howcome you can have 4 keys programmed to the vehicle, but there are only 3 FOB codes in the BECM? I thought they all had to be different?

I can't remember where I read it (either here or on RR.net) but someone mentioned that they couldn't get a key 2 anymore, only key 1. Looking at Rimmer Bros website it says Key 2 - No Longer Available (use Key 1). Might not be true though.

Don't know which one you need but I thought i'd mention it.

martyuk said:

+1 aswell.

If you have memory seats on the drivers side, you can find out if you have Key 1 or Key 2 if the sticker has gone (like in my case)

Save memory preset 1 at one extreme of the seat travel
Save memory preset 2 at the other extreme of seat travel
Set seat in middle of travel
Superlock the vehicle

On unlocking 'Lazy Unlock' (Press and hold the unlock button on the remote, or turn and hold the key in the door to the unlock position)

The seat will move to whatever preset the key is (memory 1 for key 1, memory 2 for key 2)

If the seat doesn't move, then either the vehicle wasn't superlocked, or your lazy unlocking didn't work... or you have a Key 3 or Key 4.


Worked for me, as I said - I found out I have Key 2 - so will re-order another Key 1 at some point...

Here's another question though for those 'in the know' about BECM's an keys...

Howcome you can have 4 keys programmed to the vehicle, but there are only 3 FOB codes in the BECM? I thought they all had to be different?

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I dont think the BECM fob codes refer to inidividual number fobs,but a specific key fob "family" consisting of fobs 1-4.

JohnP38 said:

I dont think the BECM fob codes refer to inidividual number fobs,but a specific key fob "family" consisting of fobs 1-4.

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Hi John,

I did wonder that, so if the FOB codes consist of all the keys 1-4 in a "family", how does the BECM then tell them apart (like for Keys 1 & 2 for memory seats or just in general, so you can't have more than one Key 1/2 synchronised at one time?)

I'm just curious to know how the system works in a bit more depth!!

Marty

martyuk said:

Hi John,

I did wonder that, so if the FOB codes consist of all the keys 1-4 in a "family", how does the BECM then tell them apart (like for Keys 1 & 2 for memory seats or just in general, so you can't have more than one Key 1/2 synchronised at one time?)

I'm just curious to know how the system works in a bit more depth!!

Marty

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As far as I can tell, there is a common FOB recognition code unique to the car/ FOB set plus an additional code for each FOB.

Hi Marty, I dont know for sure but I expect each fob transmits its family code along with specific fob identiifcation information to the BECM.The reason you cant have two same number fobs synced at the same time is for security.
I have played around a bit with the fob codes in the BECM.I changed the code in the BECM to another known fob family from a different vehicle and that vehicles fobs then locked/unlocked my P38.

JohnP38 said:

Hi Marty, I dont know for sure but I expect each fob transmits its family code along with specific fob identiifcation information to the BECM.The reason you cant have two same number fobs synced at the same time is for security.
I have played around a bit with the fob codes in the BECM.I changed the code in the BECM to another known fob family from a different vehicle and that vehicles fobs then locked/unlocked my P38.

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Hi John,

Interesting...

I wonder of all 3 sets of 3 digits are required for the FOB code, or whether you could say have the first FOB code from one vehicle, and the second FOB code from another, so then a spare key from a different vehicle could then become a second key to the first vehicle (say if you bought a BECM with keys etc)

I doubt this would work if the FOB code needs to be all of the 9 digits though - you'd probably end up with a confused BECM!

Would be in interesting experiment though...

martyuk said:

Hi John,

Interesting...

I wonder of all 3 sets of 3 digits are required for the FOB code, or whether you could say have the first FOB code from one vehicle, and the second FOB code from another, so then a spare key from a different vehicle could then become a second key to the first vehicle (say if you bought a BECM with keys etc)

I doubt this would work if the FOB code needs to be all of the 9 digits though - you'd probably end up with a confused BECM!

Would be in interesting experiment though...

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confused becm ?????????? you've confused everbody now !!!!!!!!!!! the mind boggles .ha ha ha

Maybe owning P38's for so long has finally driven me around the bend!

martyuk said:

Hi John,

Interesting...

I wonder of all 3 sets of 3 digits are required for the FOB code, or whether you could say have the first FOB code from one vehicle, and the second FOB code from another, so then a spare key from a different vehicle could then become a second key to the first vehicle (say if you bought a BECM with keys etc)

I doubt this would work if the FOB code needs to be all of the 9 digits though - you'd probably end up with a confused BECM!

Would be in interesting experiment though...

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If that is possible,then you need to know what each digit of the nine signifies in order to have the correct code set in the BECM.To try it by experiment could be frustrating.Need to do the maths to see the number of different number combinations possible

Sounds like something else for the too hard basket at the moment!!!

It's even more complicated because at least part of the code is a rolling code, hence the reason the FOB can go out of sync if the rolling code has moved on too far.

Datatek said:

It's even more complicated because at least part of the code is a rolling code, hence the reason the FOB can go out of sync if the rolling code has moved on too far.

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Interesting... I thought that the rolling code would have been seperate. From what I've read on the likes of the BBS website, the FOB code is somehow derived from the lockset barcode number?

Either way... the system is definitely pretty advanced for something that was designed in the early 90's! I wonder if LR ever thought it would be a bit of an overkill!!

martyuk said:

Interesting... I thought that the rolling code would have been seperate. From what I've read on the likes of the BBS website, the FOB code is somehow derived from the lockset barcode number?

Either way... the system is definitely pretty advanced for something that was designed in the early 90's! I wonder if LR ever thought it would be a bit of an overkill!!

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Not that advance, rolling code FOB operated alarm systems were available in the eighties. The code transmitted appears to me as one long code string, not got the kit to identify exactly what changes but it certainy does change.