I have a 2000 honda civic ex that I have recently replaced the motor. The car runs great but my engine light came a week later. The code that comes up is p740. I used vavoline transmisson fluid that stated it was good for imports. I have a new torque converter and I have also replaced the vavoline trani fluid with honda trani fluid. My question is, what can I do to fix this. I'm not a mechanic but I can turn a bolt or two. Any help is welcome

 

P740 is Lock Up Control System and unless you have the tools it is not something you can do yourself.

The first test is to check line pressure.

About the only thing you can do is toss parts at it, replace the Lock Up Control Solenoid Valve A/B Assembly and see if that solves your problem, however, tossing parts at a problem is an expensive way to troubleshoot a problem. 94

 

Did you ever solve this problem? I’ve got the same thing on an 02 Civic that got a new tranny at 79k miles now at 160k. No symptoms. Just throws the code. Runs great. Thx.