The transmission on my 1997 Civic won't always lockup and is getting progressively worse. I have monitored the voltage to the lockup solenoid when driving and there is 13V when lockup occurs and 0V when it won't lockup, so the ECM apparently isn't always providing the signal to the lockup solenoid. I know one condition that must be met prior to lockup is engine temperature and that is okay. What other sensors does the ECM get data from before allowing lockup to occur?
Also, why are there two lockup solenoids? Must both solenoids be energized for lockup to occur?