ECU / TCU Replacement options?

[KitsunEX-R]

Hi all,

so it looks like my TCU's gone bad. Last night I was driving home and the automatic transmission kinda just got stuck in 4th gear. When I stopped the car and restarted it, the shift lock wouldn't disengage. I unlocked it manually and started the car in Neutral, then drove around a bit. Seems like I can shift up manually through all the gears, but if I just leave it in D4 it won't shift at all.

I checked around and noticed that a few people have had problems with the TCU burning out on these cars, so I went and pulled the codes and got a steady CEL light and nothing from the "S" light at all. A 0 code on the CEL indicates faulty ECU so it looks like I'm left having to replace the whole shebang.

Now the important part: I'm driving a 91 Auto EX-R Coupe and am curious where I should look for a replacement ECU/TCU? Should I try and find one from exactly the same model as my car? Is there a better (gas mileage, performance) ECU/TCU From another car that might be a better investment right now? I know there's another auto 91 EX-R Coupe at a scrapyard near my place, but I'm not sure I wanna go buy the ECU/TCU out of that one only to have it already be bad or go bad on me quickly.

Any thoughts guys? Any contacts who might supply someone up in Montreal with a new unit? Are they still available from Honda directly? Hell, any advice would be great right about now. The CB's my daily driver so getting this fixed as quickly and as reliably as possible is my top priority right now

Thanks!

[KitsunEX-R]

Evening bump ^^

C'mon I know some of you out there must know where I can get an aftermarket TCU, or if Honda Dealerships can get me a new one.

[ACCLUDE91]

Well, the most common cause of TCM failure is fried resistors inside the TCM. Pop the cover off and look. You might also be able to smell them without even poping the cover off. Anyways, you could look at another TCM and see what parts and their values and just desolder the burnt shit and solder in the new stuff. It will cost you less than $20 to do it this way. Paying for a rebuild will cost you about $100. A used replacement TCM will set you back about $150-200. This is in USD. You need to match the part number as close as possible if you replace it. I may be wrong, but I believe the DX/LX has different shifting points or slightly different programming than yours. I'm not aware of any upgrade options so maybe others can fill in there? I'd think the H22/H23 TCM wouldn't offer any gains over the F22 because of the gearing differences. Anybody?

[tommi]

another thing check the fluid level in the tranny itself, or maybe the solinoids ontop of the tranny is fuct or lastly the tcu is fried. lemme know i have replacements if you need.

[peego]

not hijacking your forum

i have the same problem in my 92 lx 4dr wondering if i could used a tcm from a 90-91 lx in my 92 lx (anbody). thanx

[KitsunEX-R]

i have the same problem in my 92 lx 4dr wondering if i could used a tcm from a 90-91 lx in my 92 lx (anbody). thanx

From what I've read, no you can't. The 90-91 models had a Sports Mode which was removed from the 92-93 models and replaced by a somewhat significantly different usage of 3rd gear. It would be best to try and find a TCU from a 92-93 LX for your case.

-But-

After replacing my TCU with a compatible unit, the problem persists exactly the same. I'm still not getting any codes from the TCU, but pressing my Sports button won't light up the "S" light on my dash either. I've done some finer checking and it seems I'm only getting 1st and 3rd gears from my tranny, even when I'm shifting manually.

Since the problem is independant of the TCU, I'm now looking into other possibilities (good thing my scrapyard has a returns policy!)

I can't hear the Shifter Release solenoid clicking when I step on the brakes, so that might busted, but wouldn't explain the lack of shifting from my transmission once I get going. Might be the Shift Solenoid assembly is bad, so I'll try checking those out next.

Anyone know if I can reach them from the top of the Engine Bay? Judging from the diagram in the Honda Service Manual it looks like I might have to get her up on a lift to replace/test these out... which would suck, since I don't have access to one