Got a 1998 Civic EX & I'm the original owner, 260,000 miles. Several weeks ago I got the 'dreaded' P0700 & P0740 codes. Other than the lockup solenoid not working, the transmission shifts fine. I went ahead and did the 3 time, 3 quart fluid change (9 Qt total w/ DW-1 Honda fluid), and went ahead and replaced the old lockup solenoid with a new Honda part (#28300-P24-J01). I checked the old one and it checked out fine (ohm check and seeing if the solenoid still was clicking on both solenoids), but I decided to go ahead & replace it anyway. Now the transmission shifts great, smooth with no slippage, but that new lockup solenoid isn't working. I'm guessing that the only thing left to do now is to have it rebuilt??......any other suggestions?? Also, even after 260,000 miles (fluid was only changed once by the dealer back in 2003), there was very little material on the magnetic drain plug. What's gonna happen if I keep driving it like this?? The estimate for a rebuild is $1800.00 to $2250.00!! Damn, the car probably isn't worth that!

 

Check that there is power to the solenoid wiring. If you get the code immediately when you turn the key on, the ECU has detected an electrical problem-- it wouldn't be a mechanical problem in the transmission. This may be one of the fuse 15 related parts.

I think that the lock-up is done in the torque converter itself, you may only need to swap the converter for a used one instead of the whole transmission. Anyway you can buy a whole used transmission for much less than $1800.

 

One thing that I haven't checked into is wether or not there could be a blown fuse. Is there a fuse or relay that controls this solenoid? That could be a problem as well & is something that I haven't checked into......I will check that fuse '15'; it very well could be blown. Is this under the fuse block under the hood on under the dash?

Yes, I could find a 'used' transmission. but you never know about those and how long they will last. Too much of a gamble for me.

 

I pulled that 7.5 amp back up fuse. Now the check engine light is off, but will certainly pop back on when I drive it; I guess that it's not an electrical problem.

It must be a line pressure issue & I'm sure that I'll have to have it rebuilt. A used one isn't an option for me, and a new one is out of the question. It's ashame because the transmission shifts just fine, especially since I just did a fluid change.

 

I also noticed that there's a 'shift solenoid' that's mounted on the tranny down below that's close to the drain plug; in the Haynes repair manual, it states that if you replace the lockup solenoid, that you should also replace the shift control solenoid. Any reason for this and could this also be a reason that the NEW lockup solenoid that I installed still doesn't work?? Would be nice to find out before I go and spend additional $$$$ on another solenoid that I might not need.

 

If you are already considering for auto transmission rebuild Cucamonga, CA, then I think you should look someplace nice. Because sometimes they can be very expensive try some local garage or motor shop that are famous for Honda Civic.