Overdrive not working

[raymoneymacias]

I have a 93 LX and for some reason my overdrive (I think that’s the issue) won’t turn on or something and I can’t go into 4th gear. I’ll get to 40ish and then it just becomes like a neutral. Not sure what the issue is. Any tips or fixes?

[deevergote]

I don’t know much about autos, but most issues that aren’t purely mechanical (like a torque converter) are usually TCU related. Swap out your transmission computer for another from the same year and model (92-93 LX or DX should be identical… EX and SE would probably work fine as well.)
Or if you’re handy with electronics, examine the board. Replace any damaged parts (I believe it’s often a bad resistor) and carefully check the solder joints.

You could also change your fluid, as it could very well be from 1993 if you haven’t done it. Use Honda ATF. The autos tend to be sensitive to fluid types, and non-Honda fluid frequently causes issues.

[raymoneymacias]

Thank you man, it’s my first car so I’m not sure exactly but that was really helpful thank you

[Grumpys93]

Does d4 flash at all? Or do you have a check engine light on?

[rps]

Drain and replace transmission fluid with Honda fluid, clean the two transmission solenoids. Check out electrically if they are engaging also. The third thing is to adjust the throttle an shift cable lines. Good luck!

[raymoneymacias]

My d4 doesn’t really flash, but it stays on when I’m in park and when I drive it also stays on, like if I put it in d3, the d4 will stay lit. It feels really underpowered when it stays on but after a while it goes back to normal

[Grumpys93]

https://www.cb7tuner.com/vbb5/forum/...nd-s-d4-errors

[DJOLMNHJ]

Mine was damaged due to a rude driveway and I was unable to find the OEM part. The best I came up with was this: https://www.superdriveusa.com/. It was a loittle more than I wanted to spend, but the car looks much better overall.