Fox Body ECU Guide

Fox Body ECU Guide - Fox Body Mustang Forum

Hey guys, thought I’d make a quick guide on the codes to identify the different ECUs in Foxes

Code Guide

1988 MANUAL - 8LD
1988 AUTO - 8LF
1989 MANUAL - A9L, A9S
1989 AUTO - A9P, A9T
1990-92 MANUAL - A9L
1990-92 AUTO - A9P
1993 MANUAL - A3M
1993 AUTO - C3W
1993 COBRA - X3Z

What Swaps?

It’s important to note that different years can have different harnesses, so that should be checked before any ECU swap.
Automatic ECUs can be used on manual cars, but manual ECUs cannot be used with automatic cars.

Which One Do I Want?

Usually, the most desirable ECUs are the ones from mass air cars rather than speed density equipped cars (money wise). Obviously, you don’t want the ECU from a speed density if you have mass air (or visa versa). The most sought after ECUs for performance are anything starting with the A9 code. \

Hope this helps!