Transmission & Differential - Transmission Problem

I have a 2000 Honda Civic LX with AT transmission, transmision does not change gear, it is always on 4th gear unless manually moved to 3 or 2, transmission light is blinking, transmission works OK once I start moving in 2nd and then change to 4th gear.
I got the following fault code when I used the scanner:
P0505 idle control system malfunction
P1298: Electrical Load Detector circuit high
P1753: Torque convertor clutch solonoid valve circuit
P1768: I CAN NOT FIND decription for this code
Can someone tell me what is wrong with this car and what part(s) I need to change.

take it back to the dealer or a local mechanic that you trust. it'll probably be expensive considering what you've listed.