Page 1 of 1

The CAN System & Transponder Interface Chip #PCF7941

Posted: 2007 Mar 29 16:55
by Tiff
Anyone have any experience with reading/flashing the PCF7941 chip in the new CAN transponder remote keys?

From my understanding when one of these keys are programmed to a vehicle, vehicle specific information is transfered and stored in the EEPROM section of this chip making the key only useable on one vehicle.

To put it simply, transponder remote CAN keys can't be reused on another vehicle.

I was wondering if the EEPROM information in the chip of a new can remote key was blank (unmodified) or once assembled, flashed with chrysler information that ready's the key for programming.

I have over 75 of these used keys that i would like to at some point have reflashed or replace their chips to make them usable again.

I have access to all the CAN system passwords (do not ask for any, I can't give them out), response codes & diagnostic equipment to program new keys to vehicles, but would like to be able to re-activate my used inventory.

With the cost of new key blanks at $50 to $100, a transponder chip reflasher would definatly make good financial sense.

Posted: 2007 Apr 16 15:07
by este00
I would keep reading on the system if I were you.

I know for a fact the dealer (with the correct PIN number) can learn any key to any vehicle. I know this b/c I have done it.

I would ask a locksmith if I were you, they have 3rd party tools that do all the transponder work for all vehicles.

C.A.N. Remote Keys Can Be Reprogramed, But With A Catch!

Posted: 2007 Apr 18 00:41
by Tiff
I am a locksmith with all of the 3rd party tools to which you speak. Yes, C.A.N. remote keys can be re-programed but there is a catch. If vehicle keys are ever lost or stolen, the car's immobilizer system can be wiped clear erasing all keys from the car's memory. Then these used keys can be re-programed again, but only to the original vehicle to which it was first programmed.

This can be accomplished because the original specific vehicle information still resides in the key's EEPROM chip. When you try to program a used key to another vehicle that it was not originally programmed to the Transponder Diagnostic Programmer always comes up with an "Error". I suspect this due to the fact that the programmer is trying to overwrite the new vehicles information over the old in the EEPROM chip. I don't know of any dealerships that save used keys with spent blades and chips, swapping them from car to car. They just sell new stock. A company over in Great Britain has announced that it will be looking into C.A.N. remote key re-flashing to see if the used chips can be re-flashed back to new making them usable again. But I am not aware of when this research will be taking place.

Re: The CAN System & Transponder Interface Chip #PCF7941

Posted: 2011 Oct 05 01:10
by carkeys

How is that the big button remote head transponder keys can be unlocked, but the small button remote head keys & Fobiks require some "secret" that only a very limited few people know how it's done? And their lips are sealed!!