I have been reading around the forum on the 575 Fiorano 175891 Steering ECU fittment on the 456 GTM Does anyone know if this is compatible with the 456 GT? my car is 1996 build number greater than 21xxx My Servotronic ECU p/n is 7038900249. pic attached. I also read some have made custom steering ECUs as well. are any of these available? If none are compatible to the 456 GT, has someone managed to modify a stanard ECU to "stiffen" the steering? Image Unavailable, Please Login
So far, the only work has been on the Hydraulic Steering ECU for the 456M, 550, and 575. Have not seen anything done on the 456 GT ECU, including Maranello Skunkworks.
The 456 GT servotronics ECU looks the same as the M. I wouldn't be surprised if it worked fine with it. Surprised nobody has tried it yet.
I just talked with MSW, John says the 456GT is a different form factor from the 456M and later steering ECU's and is not compatible. He says he has not been able to 'hack' into the 456GT module to make any changes.
To clarify my comments, John says that, no the 456M and 550 steering ECU will not fit into the socket for the 456GT. He also said he has not been able to get his hands on a 456GT steering ECU to see if he can "hack" it and change the programming. If someone has a 456GT steering ECU they are will to be a test case and send to him, I believe John is willing to try to modify it.
I don’t think that’s necessary….From memory - very early GT has a completely different steering control module than the later GT and the even later M < John was referencing this very early type. That photo looks like later GT and can be easily remapped / swapped Though fwiw, I don’t know the native coding on that late GT module nor how it compares vs the later M or 550/575 controllers. (Which is saying something as I do have most the other ZF maps from when I did a deep dive reverse engineering the system to adapt for my e31…) Short version - John’s controller should work in your car.
Correct, the early steering modules look like this: Image Unavailable, Please Login Image Unavailable, Please Login But whether P/N 166852 (later 456GT) is compatible with P/N 174763 (456M), I don't know.
How many pins does your module have? The 456M has 6 pins: Image Unavailable, Please Login The small pin is a diagnostic pin, but it's disabled on the 456M.
