Just bought a 1992 accord LX w/160k. The D4 is always lit and the car won't shift gears at all. In order to drive the car you have to start in D1 then manually shift to D3. The D4 is on solid no flashing. In looking at some other threads it is suggested that the TCM is bad. I would like to narrow this down a little before I replace the TCM. I have flushed the fluid twice and added lucus.

There seems to be a maintenance flag on the left side of the dash (maintenance required), what does this mean and how do I clear it.

I have seen several threads about an "S light". can someone explain, I don't seem to be able to find a light or a switch for this.

Very common problem for 90-93 Accords...

It could be your TCM or your speed sensor(pulsar).
Usually if its the speed sensor you will lose your speedo as well.
Mine did the same thing your's is doing and it turned out to be the TCM,but I didn't find that out until after I replaced the speed sensor.

maintenance required flag is just an idiot device to remind you to have regular service done...it runs off of the odometer and changes from green--yellow--red as miles click by...i have a 5thgen but to reset mine there is a slot in the guage cluster to stick the key in and that resets it.

I have seen several threads about an "S light". can someone explain, I don't seem to be able to find a light or a switch for this.

Not sure if the 92 still had that - my 93 doesn't.

Don't lose any sleep over it - it wasn't much use, and if you don't see a green light with "S" in it in your instrument cluster, then you're fine.

BTW, it sounds like you don't have an owner's manual. Some of the stuff you asked is answered in that. I may have a spare I can sell you for a nominal sum.

It's your TCM. Very common problem for 90-93 Accord. I replaced mine last year for this problem. Try to move the shift stick out of Parking position without starting the engine or depressing the brake, you should be able to. That confirms the TCM.

I have a good TCM I can sell you pretty cheap if your interested...
http://www.automotiveforums.com/vbulletin/showthread.php?t=283907

replaced TCM problem solved.......thanks

cleared maintenance flag...........thanks

no "S light".........thanks

hope I can return the help sometime.