1990 Accord LX Transmssion Problems - Please Help
 

Greetings, I apologize for the length, but I want to be as descriptive as possible.

I was hoping to get some insight into a problem that I have. Any feedback is greatly appreciated.

I have 1990 Honda accord LX automatic (97, 000 miles-drive by senior citizens) with some problems in the transmission. First the car would start out only in 4th gear, and would only downshift manually into 2nd with the gear selector. I attempted to fix the problem by replacing the TCM out of a 92, but the situation did not change. I also opened up the 1990 TCM and noticed no "burned resistors". After this I changed the fluid(3 times driving in between runs), which was fairly black, and the each time the plug was covered in a very fine metallic sludge. This did not help the problem.

Next I replaced the transmission solenoids from a junkyard car (92 accord), and I got first gear back. Now it doesn't shift, out of 1st, but once I drive it and it tries to shift out of 1st, I loose all gears (freely revs in all gear selections-neutral), and I have to turn off the car, wait a a minute, and I get 1st and Reverse back again, but only until it happens again. One last thing..... sometimes when it tries to find revers, it grinds a little bit until it finds it, and then engages.

Now for some important information. I am getting a code 15 from the transmission control module LED light, and after tenacious searching on the web, I found the list of codes, which states it is a "mainshaft speed sensor failure".

Does anyone know where this is, and if it will help the problem? I really don't want to believe this car needs a new transmission, and it doesn't slip in any of the gears (once it finds them). I refuse to believe this 1990 accord needs a new transmission at 97,000 miles only.

Any insight would be greatly appreiciated. The speedometer does work, and I don't get any flashing S or D4 lights.

Thanks much to anyone who replies.

Re: 1990 Accord LX Transmssion Problems - Please Help (hatzipri90accord)
 

I have a similar problem, Your first mistake was getting a new tcm out of an 92 accord, cause they use a different tcm. You tcm has to come out of an 90-91 accord lx or dx. I think your problems are tcm related.

Re: 1990 Accord LX Transmssion Problems - Please Help (Broman78)
 

Thanks for the reply. Are you sure about this? When I put the 92 TCM in and drove it, it didn't drive any better, but flashed the S light solid. If I put in a 90-91 it will improve? I didn't see any burn marks on the circuit board when I opened up the TCM (which is a common indication of a failed TCM). What about the code that I am getting?

Thanks for the reply.

hey i was wondering how much do those tcms cost?

???

Re: 1990 Accord LX Transmssion Problems - Please Help (hatzipri90accord)
 

you need to use a TCM from the same year(s) of car that you have. Honda cold have made some changes in the design in 92 that are not compatable with a '90 car. Since you mentioned an excessive amount of metal in the fluid, I would also be looking for a new tranny...

Re: 1990 Accord LX Tranmssion Problem - Please Help
 

I have a 92 Honda accord EX and my D4 light flashes y?

Re: 1990 Accord LX Tranmssion Problem - Please Help
 

Because the tcm/tcu has sensed a fault and the flashing is to tell you there is a code set. Retrieve the code and get back to us.