How the FIM Programable Eprom Works

[Shazaam]

I had a misconception regarding how the FIM chip system works, so I thought I’d pass this information on. I assume it will be of general interest to the forum members.

A question arose where a 996 owner had installed a custom FIM chip that matched his aftermarket exhaust system. The owner had then tweaked the setup further and saved the new settings using the FIM software from his laptop.

Now, I assumed that the chip that FIM uses is an EEPROM (electronically erasable programmable read only memory) that can be altered electronically - unlike a factory-issue EPROM (electronically programmable read only memory) that needs to wiped by exposure to ultra violet light in order to be reprogrammed. I thought this is what makes FIM chips unique - their ability to be programmed repeatedly. Both chip types retain their program/data forever without power.

Anyway, the owner asked whether the additional tweaks that he made were transferred to another 1.6M computer if he took the FIM chip out and reinstalled it in the second ECU.

I always assumed that the settings were written to the FIM chip and would be transfered with the chip swap. Not so ...

Here’s Duane Mitchell’s (Ultimap/FIM) explanation:

“The FIM EPROM are the same as a factory EPROM in that it cannot be reprogrammed while they are in the ECU. They are EPROM, not EEPROM.

Our zone system works as follows:

The ECU contains an EEPROM which can be written-to while the engine is running. This is used to store 'original' software variables such as stored fault codes, but little else. We use the spare EEPROM in the ECU to store our 8 zones (one overall trim and 7 specific zones), as well as our maximum RPM telltale and a few other things accessible with our hand terminals and PC software.

When an Ultimap chip is fitted to a 'virgin' ECU (one that has never used our stuff before) it checks the zone area and if it's found blank it puts zero trims in all locations. Then when you trim the ECU using the HHT the locations are modified and work as a fuel trim 'overlay' on the contents of the map stored in the EPROM. This overlay is non-volatile and held in the ECU.

So, if you remove the Ultimap chip and place a stock chip in the ECU, these locations are ignored and the ECU runs dead stock. Or, if you place the Ultimap chip in another ECU, it will look for these locations and use the overlay in that ECU to modify the chip maps.

So, the zone trims are stored not in the chip, but in the ECU, and they will work on ANY Ultimap chip used in that ECU, and DO NOT affect the chip's operation in another ECU.”

The interesting corollary to all this is that once you’ve programmed a FIM chip in it’s ECU, if you put a different FIM chip into that same ECU, the overlays for the first chip will be applied to the second chip - unless you clear the overlays first.

According to Duane:

“The only way to clear the zones is with our HHT (no longer manufactured) or PC diagnostic program used by BCM, etc. Neither the Mathesis or MDST-type programs do this since they do not use our communications protocols.”

Cool Eh?

[GasGas]

I live in Dallas and heard that Advanced Motorsports had the HHT programer for these overlays but what if I needed these ECM tweeks done elase where sense The Utimap guy said that the HHT device was out of production??
Signed, GasGas

[i drive a honda]

Originally Posted by Shazaam

I had a misconception regarding how the FIM chip system works, so I thought I’d pass this information on. I assume it will be of general interest to the forum members.

A question arose where a 996 owner had installed a custom FIM chip that matched his aftermarket exhaust system. The owner had then tweaked the setup further and saved the new settings using the FIM software from his laptop.

Now, I assumed that the chip that FIM uses is an EEPROM (electronically erasable programmable read only memory) that can be altered electronically - unlike a factory-issue EPROM (electronically programmable read only memory) that needs to wiped by exposure to ultra violet light in order to be reprogrammed. I thought this is what makes FIM chips unique - their ability to be programmed repeatedly. Both chip types retain their program/data forever without power.

Anyway, the owner asked whether the additional tweaks that he made were transferred to another 1.6M computer if he took the FIM chip out and reinstalled it in the second ECU.

I always assumed that the settings were written to the FIM chip and would be transfered with the chip swap. Not so ...

Here’s Duane Mitchell’s (Ultimap/FIM) explanation:

“The FIM EPROM are the same as a factory EPROM in that it cannot be reprogrammed while they are in the ECU. They are EPROM, not EEPROM.

Our zone system works as follows:

The ECU contains an EEPROM which can be written-to while the engine is running. This is used to store 'original' software variables such as stored fault codes, but little else. We use the spare EEPROM in the ECU to store our 8 zones (one overall trim and 7 specific zones), as well as our maximum RPM telltale and a few other things accessible with our hand terminals and PC software.

When an Ultimap chip is fitted to a 'virgin' ECU (one that has never used our stuff before) it checks the zone area and if it's found blank it puts zero trims in all locations. Then when you trim the ECU using the HHT the locations are modified and work as a fuel trim 'overlay' on the contents of the map stored in the EPROM. This overlay is non-volatile and held in the ECU.

So, if you remove the Ultimap chip and place a stock chip in the ECU, these locations are ignored and the ECU runs dead stock. Or, if you place the Ultimap chip in another ECU, it will look for these locations and use the overlay in that ECU to modify the chip maps.

So, the zone trims are stored not in the chip, but in the ECU, and they will work on ANY Ultimap chip used in that ECU, and DO NOT affect the chip's operation in another ECU.”

The interesting corollary to all this is that once you’ve programmed a FIM chip in it’s ECU, if you put a different FIM chip into that same ECU, the overlays for the first chip will be applied to the second chip - unless you clear the overlays first.

According to Duane:

“The only way to clear the zones is with our HHT (no longer manufactured) or PC diagnostic program used by BCM, etc. Neither the Mathesis or MDST-type programs do this since they do not use our communications protocols.”

Cool Eh?

i know this is old, but can you guys also make your own mas then burn to eeproms?

in older car ecu's 0bd0 and obd1, it is common practice to download programns (that originated as hex editors) to edit a "fuel and ignition map" solder a zero insertion force socket to where the stock eprom usally goes. so that the eeprom can be eaisly removed, easily adn quickly and replaced like a computer cpu

[CrimsonCloak]

Try this thread:

http://www.speedzilla.com/forums/duc...ware-free.html

[i drive a honda]

Originally Posted by CrimsonCloak

Try this thread:

http://www.speedzilla.com/forums/duc...ware-free.html

can't thank you enough for that, i appreciate that