I have a friend with a 2004 civic. a few days ago her transmission started acting up. She took to a mechanic and he changed the tranny fluid, now it has no forward gears. It will go into reverse fine, but putting it into any forward gear is the same as putting it into neutral. I'm wondering if it could be a faulty solenoid? The mechanic wants to replace the transmission. I don't trust him.

Thanks in advance for any suggestions.

 

Automatic transmission correct?
Check for correct level of ATF. ATF is checked within 1 minute of turning off engine after up to operating temps. Check for ATF leaks.
To confirm, you can move in R but not in D, D3, D2 and 1?
Over time the internal filter and the solenoid filters can become restricted with clutch debris. This will cause a lack of fluid pressure to change gears. The mechanic may have made this situation worse if 1) Honda DW-1 ATF was not used and 2) a power flush was done and not the recommended drain and fill method of ATF replacement. A re-manufactured transmission or a donor 2004 transmission would be the options. At this point in its life-cycle, it might be a tough decision to sink that kind of $ in it.
I feel your pain - I had an 01 Odyssey with 4-speed auto and it crapped out on me (actually scared me to death when it finally conked out) but did not fix but rather traded it in. I currently have an 03 Acura EL (fancy Civic) with a similar 4-speed but am having better luck with it at 130K miles.
Here's the troubleshooting in the attachment:

 

Hey NDNV,

Thanks for the reply. Looking over the diagnostic procedures, I’m not equipped tool/facility wise to do the work myself. I think the best I can do to help is make sure she goes to a reputable mechanic.

thanks again

 

I know a lot of time has passed but I'm having the same issues with my 2005 Civic Ex. Did you ever figure out what was causing this?