1990 Accord TCM

[gauger]

I have trans shifting problems and my description matches many I found on the web to a "T". The responses have all been that the TCM is famous for going bad on these cars. I have also been told that the TCM is under the right floor board. Question: what is the rapid clicking sound that I hear coming from the driver's side dash area?? It sounds like a solenoid or relay that is malfunctioning. BTW, the symptoms are: "S" light stays on, car starts out in D2 and stays there. I can manually put in in D1 or reverse. I can manually upshift to D2 but it will not go to D3. Any ideas?

[mpumas]

Does your speedometer work? If it does you need to short the service connector located on the passenger side kick panel under the dash (same one for the ECU). Turn on the key and count flashing D4 or S lights. If none, it might be the TCU. If your speedometer doesn't work, it might be the speed pulser/sensor.

[jeffcoslacker]

When's it click? When a shift point comes up, any time the key is on, only in motion, etc?

[Igovert500]

TCU/TCM (tranny control module/unit): Similar symptoms as the VSS, yet this may cause shifting problems, you may lose 4th gear, and you wont have issues with cruise control/speedo/or tachometer. If you do a search for TCU or TCM, you can find quite a bit of info, but basically it is a little electronic box under the kickboard of the passenger seat (where the passenger's feet would be up near the dash) You pull back the carpet, and behind that metal shield there are 2 computer boxes...I forget which is the TCU (I want to say the one on the right, but double check that before you take my word on it). Anyway, the dealership will charge huge amounts of money for a new one. So go to your local junkyard or ask around on here. Typically you can find a used one for $50 or less. It takes 15 minutes for the average person to swap.

try www.car-part.com Sometimes you can find great deals there, without having to go to the local junkyard.