1G Difference between E and M ECUs

[BillyDanks]

Could someone plz tell me if and what the diffence is between,
md165531 E and md165531 M ... I have had both into a 91 talon tsi auto and the E seems to be fine but the m does working trans right so it stays in thrid gear... i thought it was an Ecu for a stick shift so i borrowed my friends ecu out of a 91 talon tsi 5-speed, it seems to work in my auto just fine.. Please Help!! Thanks

 

[Zerocygnal]

The MD165531 is a Federal Automatic Transmission EPROM ECU hence the code letter "E" in the bottom right hand corner. The other is the same thing without the EPROM. For more information about the EPROM visit TMO.com. From first hand experience a DSM that had an EPROM ECU will not be compatible with a NON-EPROM ECU. However it is possible to take a DSM that did not have one and install an ECU that is equiped with the EPROM.
For more ECU variance check http://vfaq.com/mods/ECUs.html