91Accordkid

Hello I have a 1991 Accord LX 2dr Coupe. I replaced the TCU "Had very hard shifts" I have lost the original tcu and the new one I installed always keeps the S light on. I press and depress the button and it does not turn off. I have checked for codes but the light does not blink just stays solid. This was half a year ago and now im looking to get rid of the light by replacing the tcu with one that is correct.

So my question is does anyone know the correct TCU that I should install? Or at least the serial number. Im assuming the computers for the sport option and different from the regular computers. Thanks for looking and for the help!