Hello! New guy here with a TCU problem. I tried searching all over the internet and nothing was specific to my issue....so I guess I'll try here!

1990 accord ex, auto, 216,000 miles. The problem I'm having is the trans sometimes has a hard shift between 2nd and 3rd. It also seems like it is shifting too soon (going into 3rd at low speeds). Also at times, it is hard to pull out of "park" and other times the reverse light on the dash does not light up.

What I have tried:
I checked the TCU and got a code 5 which pointed to the shift selctor control unit. Just to be clear, I'm assuming this is the lock mechanism that releases (on the right side of the shift selector) when I hit my brake pedal...correct? If so, it seems to be working fine. After reading many posts about faulty TCU's, I pulled mine out and there is nothing burnt. All my resistors and compactors appear to be clean and not leaking.
Trans fluid is clean, up to the proper level and does not smell burnt. Though I am sure it's due to be changed.
Cleared all codes by reseting the ecu/tcu, and still have the same results.
Not sure if it's related or not but when starting the car cold, the idle does surge up and down but once it's warmed to temp it idles smooth.
No S light or D4 light are flashing or stuck on. I do have a CEL light but it shows 02 sensor....shouldn't be related to the trans issue.

If there is something else I can check or look for, please let me know. I have been searching multiple sites and forums but none of the other peoples problems seem to match mine.

 

Hello frend, 13 years latter, i have got the same code. Code 5 TCU, i try a lot of metods to resolve the error but it s imposible. How does you do to resolv the 5 error TCU? Thanks you so much

 

TCU 5 is in relation to the selector switch in the shifter.
When the shifter is in a gear, that gears light on the dash should light up.
This lets the ECU/TCU know what gear you have selected.
If a liquid has been spilt on the console or the switch is out of adjustment then a code 5 may be indicated.

Check the shifter switch.

 

Thank you for your reply. Yesterday I disassembled my entire console and moved the TRS selector and on the dashboard it marks me perfectly the gear I'm in. However, when I set any gear other than P or N, I get failure D4 code 5. In P and N it doesn't fail, all the others do. On the board the gears appear with precision but also the D4 error. I don't know what to check anymore, I've been having that problem for days