I used the search function and came up with this post:gotmylegend4free said:can somebody tell me where the ecu on a 89 2dr coupe is? is it under the passenger seat or where ur feet rest on the passenger side
Join Date: Oct 2003
Car: 1987 Legend LS Coupe Coupe's ECU IS located at the far upper left corner of the passenger carpet.
Roll back the top edge to see the LED window.
TCU is under the passenger seat.
Stock 1987 Legend LS Coupe 170k
I'm pretty sure it applies to your car also.