OK I changed the transaxle switch assymbly, but still the light on D4 still on
while in park and on when I shift from park to reverse,etc. Also it shifts into reverse and I can feel it shift to 2nd then to 3rd if i do it manualy. Is there anything else I can check that may cause this, I may be trying to avoid the obivious that the transmission is toast. Any help or advise is appreciated, thanks.

 

TCU is usually the problem, i have had this several times in my 92 and 93 cars, i pull em out and look inside and see nothing wrong but a new one has fixed at least three of them and often they will not show a fault code.
Frank Allen

 

What and where is the TCU, thanks.

 

TCU, Transmission control unit, or also called transmission computer is located under upper floor carpet on right side of car, there are two units, the small one is for transmission. bigger one for engine control.
Frank Allen

 

Thanks, TCU does it have any serviceable parts or do I have to swap out to trouble shoot? Any info is appreciated.

 

sacalait,
Just got done with this tranny issue with my 92 Honda accord. Be patient and do alot reading here or go to cb7tuner.com, and most importantly, keep an open/objective mind. I spend two days researching and reading trouble shooting with folks, some were good and others were hella excellent. What works for me, may or may not work for you, but I can honestly say. I work on my tranny for a week till I nailed it. This is the my M/O (Modis Operandi)
Swap out Tranny Fluid ( brown and smell burnt)
Pulled error codes from TCU: codes shift solenoid related.
Swap out TCU
Clean out both fem/masc TCU connections. Make sure the click nicely.
Check the connection prongs, make sure they are not rusted or broken.

In case, TC took a dump. No more D4 limp mode for me. I did take off the solenoid pack clean them out, tested them (click, click), one them had to be replace. In this case I feel that I did more than I should of, but then again, I nailed this issue. Good luck.

 

sacalait,
Just got done with this tranny issue with my 92 Honda accord. Be patient and do alot reading here or go to cb7tuner.com, and most importantly, keep an open/objective mind. I spend two days researching and reading trouble shooting with folks, some were good and others were hella excellent. What works for me, may or may not work for you, but I can honestly say. I work on my tranny for a week till I nailed it. This is the my M/O (Modis Operandi)
Swap out Tranny Fluid ( brown and smell burnt)
Pulled error codes from TCU: codes shift solenoid related.
Swap out TCU
Clean out both fem/masc TCU connections. Make sure the click nicely.
Check the connection prongs, make sure they are not rusted or broken.

In case, TC took a dump. No more D4 limp mode for me. I did take off the solenoid pack clean them out, tested them (click, click), one them had to be replace. In this case I feel that I did more than I should of, but then again, I nailed this issue. Good luck.

 

This was sent to me and very helpfull.

http://techauto.awardspace.com/transmission.html

laloquera

 

Thanks this is really helpfull thanks again

 

Update! Just wanted to say that the problem was with the TCU. It was a burnt resister 15 ohm 1/4 watt, and capacitor which leaked and cause the problem. Total cost less than $2 ! I changed them myself and its been several days now and working great. Thanks for the info and what a great site.

 

Hello all i need help here. my 92 accord lx has the D4 flashing light... i changed the TCU and the car was working find no more flashing D4. But today while driving the D4 light started flashing an i smell something burning.
I open the TCU and its burnt? same as the one that i replaced, why is this happening?
Also i had the Main relay changed too...
Can a bad solenoid cause for the TCUs to burn out??

please help...