MEngineer

Hello all,

I have a 2000 Honda Accord. I had the transmission replaced at a local shop with a new torque converter. After a little bit it threw the codes P0700 and P0740. I took it back to the shop and the replaced the transmission with another rebuilt unit. Almost immediately after getting back on the freeway it threw P0700 and P0740 again.

The shifting on the first unit did not feel confidence inspiring. On this second unit the shifting feels much nicer, but the torque converter doesn't lock up immediately when put into gear. I'll shift into reverse or D to pull out of a parking spot and I won't go anywhere. I have to rev the engine to get it to move, then it feels like the torque converter locks up and it will drive normally.

I've read the torque converter solenoid rarely ever go bad, but does that seem to be the case after two rebuilt units? when I had the first unit replaced I checked the solenoid and it clicked strongly and ohmed fine. I haven't checked it since.

Thoughts?

Thanks!
Dale

MAD_MIKE

P0700 is just a generic code, 'transmission problems' the idiot light of OBDII trans diagnostics.

If two transmissions, and probably your original, all have the same issue I would check that the wiring harness on the car is not damaged. Verify all the grounds are still attached, clean and tight, as well as check the battery is fully charged before blaming the transmission as the culprit.

P0740 from a problem the 98-02 transmissions had. There is a pressure relief valve(PRV) that can jam and or overshoot causing no flow of fluid. If a transmission is just reassembled with new clutches and seals without the needed modification done to the PRV(replacement or use of the SONNAX type) or its bore then a 'fresh' rebuild will probably have the same issues down the road.

If you can reduce delay of converter engagement by revving the engine up to 1200+ rpm AFTER shifting into gear, then it is most likely the PRV is stuck/overshooting/needs replacement.
Read the below article for further tech.
Overheated Honda Converters/740 code

MEngineer

Took it back to the shop and they put a third rebuilt transmission into it with a set of working solenoids on the top. No problems so far!