Technical key issues

[dagdromer]

When I bought the Panda I did not check if all the keys where working (again...) While inspecting the car, I was given the key with the fob, the fob worked fine, I was able to open en close all the locks with the key and obvious it started with that key. I asked if there was a second key available, which was but according to the seller he did not know if it worked....

When I tried it at home, the second key did not work. It is a proper Fiat key and it has very little wear on it and it fits all locks.

On the working key (with the fob), the actual key part did not really open nice like it was assembled incorrect. So I took it apart to find a PCB with all components on it and a separate transponder.

I took the PCB out and left the transponder in and was still able to start the car. I tried the pcb without the transponder and was able to open and close the car using the buttons but could not start the car.

MES told me that there is only one key active, one key disabled and that there is 1 remote active.

I've never seen that you can add a remote to a car but not use the transponder to start it. I think the BSI needs to come out so I can hex dump the eeprom to find out what is really happening.

 

[jackwhoo]

Yes the transponder and pcb for remote locking can be separate components.
Often with Fiat the second key is transponder only with no remote function.

 

[dagdromer]

I've never seen that, and the transponder was really bodged into the housing.

 

[jackwhoo]

Transponder a glass capsule? Or a chip?

Separate transponders was how it used to be most of the time....vw seat Audi used to use glass capsule transponders. The glass capsule was impervious to water - great

 

[dagdromer]

this is the black chip as you will find indeed in the Opel and VW cars. it is somewhat plastic soldered into the casing. There is no room for an additional transponder in the casing itself. This is the variant where the battery cover is at the bottom, not behind the actual key

 

[koalar]

There's no separate transponder in a key fob, it's soldered into the pcb

It's been dodged to get a working key by adding a separate transponder

You can not easily alter a black listed key, the body computer has to come out and the the stored list manipulated manually

 

[dagdromer]

No idea how they managed to program this into the BSI. I'm not able to replicate the process using tooling like MES. When I reprogrammed the keys using MES (after removing the blocked key) it no longer accepts the FOB.
And running a diff between the original hex and the one where I reprogrammed the keys did not give any hints, so that stays a mistery.

But after some fiddling with the HEX dump I now have 2 working keys including the FOB.

 

[koalar]

MultiECUscan

Can't program a new blank key

It can't do anything about a key that's been blacklisted

It can only add a key that have already been preprogrammed by fiat for that car

Given how easy it is to clone a working transponder, and how expensive a preprogrammed remote is from fiat, multiECUscan is of very little use and runs the risk of blacklisting a working key

MultiECUscan does many things but as far as key goes it very limited

 

[dagdromer]

I never said that I expected that MES would help me with any of the functions that you described.

MES is a nice tool with limited functions, like most of these (generic) commercial tools. If you want to do more you need fiat/dealer specific tools or be able to manually adjust settings in the dump.

as long as you use ALL the keys when reprogramming the keys (no idea why you want to do that) there should never be any blacklisted keys.

In my case, somebody previously relearned a single key (the one with the FOB) in the car, blacklisting the other key.

I manually edited the dump moving the blacklisted key to the active key list. Now a key is identified by a 4 digit hex number. But the string in the dump has 6 additional hex digits. 4 of those digits are static but 2 of them vary. These 2 you do not know. the only thing you can do is copy them from the blacklist part and hope for the best.
In my case, this resulted into a situation where I did have 2 active keys, not have any blacklisted keys and a working fob. But when I inserted the no longer blacklisted key in the car it would not start. MES showed me that this key is a new and not known by the BSI.
So I reprogrammed the keys using MES, expecting a blacklisted key again, 2 active keys and a working fob but to my surprise I got 2 active keys, no blacklisted key and no longer a working fob.

Dumping the data again got me the correct first 2 digits for the key, so I updated my earlier change with those 2 digits and tried again. This time I got 2 working keys, no blacklisted keys and a working FOB. And both keys actually start the car.
I did not test it as removing the BSI is a bit of a pain with all the connectors but I think that when I relearn the keys with MES (or similar) again the FOB will stop working.