P38 Key Fob Woes (I know probably been done to death but anyway)

I'm reasonably au fait with the options but can't decide what to do.

Basically, the sole working key fob on my 2000 P38 has died - changed batteries but no leds so think the fob is stuffed. Rather than try and get it fixed I'm happy to spring for a new fob from the dealers and this is where I'm starting to worry a bit that someone might have changed the BECM in the past as I dug out the other key fob that came with the vehicle, that's never worked, and only just noticed the key blade doesn't match. This is the list of questions I'm pondering and would be grateful if anyone has been down the same road and could advise.

-Is it worth sending the fob away to somewhere offering repairs is their success rate any good beyond changing the case, buttons/battery etc.

-If I get the dealer to check the EKA code matches with the one in their records is it fairly likely the new fob from LR will match with the BECM - The EKA I have definitely works I'm using it to unlock engine disabled every time I drive it at the moment.

-I have the original Britpart Lynx (again I know should have got Nanocom) does anyone know if it will read the current VIN stored in the BECM for peace of mind it's the original.

-Is there any advantage/disadvantage to either sending the BECM away to be unlocked will it get rid of the need to do the door lock EKA routine to start the car with just the key blade.

I was planning to buy Nanocom at some stage is it worth going the whole hog to Faultmate where I can lock/unlock the BECM myself are there any other advantages to Faultmate.

Many thanks for any answers.

BECM locked or unlocked will not effect need for EKA code. Unlocked EKA code and fob code are readable. Locked they are not. However getting someone with a Nanocom to disable EKA and immobiliser will sort your problems until you find out what is wrong. The software needed to unlock the BECM with Faultmate MSV2 is very expensive. As is MSV2 unit which is locked for use on one vehicle only, unless you pay for a very expensive licence..

having same issues m8 see my thread

Contact @MrSporty on here. He can more than likely fix your fob. I think he is on eBay but not sure what his username is.

If you send him both fobs he might be able to tell you if they match. I'm pretty sure he can tell you what code the key is using although how you read that from the BECM without specialist software I don't know. @martyuk can do it and so can @Rick-the-Pick.

Rangie Disco Sportsman said:

I dug out the other key fob that came with the vehicle, that's never worked, and only just noticed the key blade doesn't match.

Click to expand...

Wouldn't be surprised if a previous owner bought a spare key off the bay thinking it could be reprogrammed and then discovered it couldn't.

wammers said:

BECM locked or unlocked will not effect need for EKA code. Unlocked EKA code and fob code are readable. Locked they are not. However getting someone with a Nanocom to disable EKA and immobiliser will sort your problems until you find out what is wrong. The software needed to unlock the BECM with Faultmate MSV2 is very expensive. As is MSV2 unit which is locked for use on one vehicle only, unless you pay for a very expensive licence..

Click to expand...

Thanks, I was thinking of getting Nanocom in any case. If I disable the EKA and immobiliser is there any downside beyond the potential lack of security. I’II just be able to unlock the door with the dud key fob manually and start it up?

The locked to one vehicle thing would put me off the Faultmate TBH. The problem with all the different diagnostic options seems to be that none of them offer everything Testbook does and the product backed by Omitec oddly provides some of the least functionality.

On a slightly unrelated note if I kept the relatively compact Nanocom with me presumably I would no longer need the EAS kicker and could sell that on as well to fund the Nanocom purchase?

Grrrrrr said:

Wouldn't be surprised if a previous owner bought a spare key off the bay thinking it could be reprogrammed and then discovered it couldn't.

Click to expand...

Thanks for the reply

Could be - I think we’ve all been down the road of hoping you can do that. It’s sown the seed of doubt that a new fob from the dealer might not work. (Does anyone know if a normal key cutting place can cut a replacement key blade as I in fact haven’t actually got a spare key as I presumed happy not to have a remote fob on the spare)

The main problem I have, which is forcing my hand a bit, is it needs an MOT and I really can’t face the names I’d be called behind my back at the garage if I rock up and tell them they’ve got to turn the key four times to the left, three times to the right etc to start the engine. If as it sounds I can disable this with Nanocom I’II do that and it will give me a bit of time to look into getting the BECM data looked at and getting someone to look at the fobs I’ve got.

Does anyone know if I can indeed ascertain the BECM has got the right VIN on is it pretty much certain a new fob from the dealer will sync to it?

@Rangie Disco Sportsman
Nanocom will tell you the last 6 digits of the VIN that the BECM is programmed to.
From the Nanocom manual:
VIN: The last six digits of the Vehicle Identification Number (VIN) that is unique to each vehicle.
The designation for the remainder of the VIN is detailed in the relevant manual.
• An invalid format VIN number will not be accepted. The VIN cannot be changed on a Locked BECM.

And.....
FOB code: For security this information is only available to be read or programmed on unlocked BECM's (see BECM STATUS). The fob code is a 3-part code, which uniquely identifies the family of key fobs (key 1, key 2, etc.) that go with this vehicle. Any key Fob, when pressed, transmits its unique electronic ID code (FOB CODE) in an encrypted format. The BECM of any vehicle within range of that key fob decrypts the received transmission and compares the FOB CODE that was received, against the FOB CODE that is stored here. If the two match, it will accept the key as valid and perform the relevant task (lock, unlock, send mobilize signal to engine ECU, etc). This FOB CODE is derived from converting the manufacturer's Bar Set Lock code. This is a 14 digit alphanumeric number, which is printed on a label that accompanies every new key fob or lockset. When the vehicle was assembled at the factory and was first fitted with its new lock set, the Bar set lock code was recorded along with the vehicles VIN number; this can be obtained from your local dealership by quoting the Vehicle's VIN number. If the bar set lock code given by the dealer is no longer correct for the vehicle (due to an earlier replacement of the lockset and where the kept records were not updated), there is then no alternative but to replace the lockset and use the bar set lock code that comes with it. When you have the bar set lock code, do not attempt to enter this directly, but email this code to [email protected] who will then convert the bar set lock code into a the 3-part FOB CODE. This FOB CODE is then entered in this section. The FOB CODE can only be obtained by this method.

DanClarke said:

@Rangie Disco Sportsman
Nanocom will tell you the last 6 digits of the VIN that the BECM is programmed to.
From the Nanocom manual:
VIN: The last six digits of the Vehicle Identification Number (VIN) that is unique to each vehicle.
The designation for the remainder of the VIN is detailed in the relevant manual.
• An invalid format VIN number will not be accepted. The VIN cannot be changed on a Locked BECM.

And.....
FOB code: For security this information is only available to be read or programmed on unlocked BECM's (see BECM STATUS). The fob code is a 3-part code, which uniquely identifies the family of key fobs (key 1, key 2, etc.) that go with this vehicle. Any key Fob, when pressed, transmits its unique electronic ID code (FOB CODE) in an encrypted format. The BECM of any vehicle within range of that key fob decrypts the received transmission and compares the FOB CODE that was received, against the FOB CODE that is stored here. If the two match, it will accept the key as valid and perform the relevant task (lock, unlock, send mobilize signal to engine ECU, etc). This FOB CODE is derived from converting the manufacturer's Bar Set Lock code. This is a 14 digit alphanumeric number, which is printed on a label that accompanies every new key fob or lockset. When the vehicle was assembled at the factory and was first fitted with its new lock set, the Bar set lock code was recorded along with the vehicles VIN number; this can be obtained from your local dealership by quoting the Vehicle's VIN number. If the bar set lock code given by the dealer is no longer correct for the vehicle (due to an earlier replacement of the lockset and where the kept records were not updated), there is then no alternative but to replace the lockset and use the bar set lock code that comes with it. When you have the bar set lock code, do not attempt to enter this directly, but email this code to [email protected] who will then convert the bar set lock code into a the 3-part FOB CODE. This FOB CODE is then entered in this section. The FOB CODE can only be obtained by this method.

Click to expand...

Thanks, I think Nanocom might be a worthwhile investment.

The second part seems a bit unclear it seems to imply if the BECM is unlocked the fob code can be altered which would presumably permit any fob you had the code for to be entered when I thought there definitely isn’t any way of programming any BECM to any fob unless I’m misunderstanding that bit.

Rangie Disco Sportsman said:

Thanks, I think Nanocom might be a worthwhile investment.

The second part seems a bit unclear it seems to imply if the BECM is unlocked the fob code can be altered which would presumably permit any fob you had the code for to be entered when I thought there definitely isn’t any way of programming any BECM to any fob unless I’m misunderstanding that bit.

Click to expand...

I believe you are correct. A "locked" BeCM means just that. Locked to that vehicle and the FOB code the BeCM can read/recognise is unalterable.
Also from the manual:
NOTE.DO READ THE BECM STATUS REGARDING THE BECM BEING LOCKED OR UNLOCKED. THE BECM CANNOT BE UNLOCKED USING THE NANOCOM EVOLUTION

OTHER

• Software level: The software level of the BECM. This number can be read as well on the label. • Firmware: The firmware of the microprocessor fitted in BECM. This number can be read as well on the label. • VIN: The last six digits of the Vehicle Identification Number (VIN) that is unique to each vehicle. The designation for the remainder of the VIN is detailed in the relevant manual. • An invalid format VIN number will not be accepted. The VIN cannot be changed on a Locked BECM • Mileage: The value shown on the odometer display (sometimes Kilometers). This value can not be altered • Date of build: The date the BECM was built in DD MM YYYY format. ECU accepts only valid values: day between 1 and 31, month between 1 and 12, year between 1991 and 2010. • BECM Status: The BECM has an electronic lock that is designed to prevent access to some of its contents. All BECM's are locked in this way at the vehicle factory after they are programmed with the information specific to the vehicle they have been fitted in. However, replacement BECM's are supplied unlocked and all data can be readily accessed and changed up until the point when the unit is locked. This is currently an irreversible process without a Faultmate MSV-2 and special module SM035 so it is important to check the correctness of all information stored in the BECM before considering locking it. The status of the lock has no effect on any other operation of the BECM (i.e. it is perfectly acceptable to leave the status of the BECM unlocked for normal vehicle usage). Attention, if the BECM is unlocked there might be problems in communicating with HEVAC in diagnostic mode. More details in the HEVAC help page.

Find someone local to you with a Nanocom for your P38 variant (GEMS/Motronic/DSE) to read its status for you. Or, send it to someone like @Rick-the-Pick.

Rangie Disco Sportsman said:

Thanks, I think Nanocom might be a worthwhile investment.

The second part seems a bit unclear it seems to imply if the BECM is unlocked the fob code can be altered which would presumably permit any fob you had the code for to be entered when I thought there definitely isn’t any way of programming any BECM to any fob unless I’m misunderstanding that bit.

Click to expand...

Just to clarify this point. The fob codes are generally referred to in most literature as a set of 3 numerical digits, i.e 012-123-234. Converted to hexdecimal this would be : 0C7BEA.

It is the second nibble of the first byte that defines which number key of the keyset. 0/4/8/C are Key0, 1/5/9/D Key1, 2/6/A/E Key2 and 3/7/B/F are Key3. So in the example above that nibble is "C" that would be a Key0 and the other 3 keys in that keyset would be 013-123-234, 014-123-234 and 015-123-234.

The BECM stores the Key0 value and can derive the other 3 keys in the keyset from that.

So, taking a key you know the keycode for and programing its Key0 keyset value into an unlocked BECM would make it work with that BECM. Because only one value is stored, you cannot use 2 keys from differing keysets, even if they are different KeyX numbers.

i.e I have keys with codes 001-000-000 (key1) and 003-000-000 (key3) .. program an unlocked BECM with 000-000-000 and they both work as they are from the same keyset.

I have keys with codes 001-000-000 (key1) and 003-111-111 (key3) .. I can program either 000-000-000 OR 000-111-111 and have only one or the other key working but not both.

speak to mozz smith hes a legend