Code : P0740
Make : HYUNDAI
Description : P0740 HYUNDAI Torque Converter Clutch Solenoid Valve
Possible causes :
– Low transmission fluid level
– Dirty transmission fluid
– Faulty torque converter clutch solenoid valve
– Torque converter clutch solenoid valve harness is open or shorted
– Torque converter clutch solenoid valve circuit poor electrical connection
Solutions :
– Carry out a Reset via CarDiag
– Choose a better quality fuel
– Check that the tank cap is securely closed
– Check the oil level and add more if it is lower than MAX
– Restart an Automatic diagnostic via CarDiag
– If the fault persists, you can check the “Possible causes” listed above : visually inspect (by yourself (tutorials to come) or by a professional) the wiring harness and the associated connectors, check for damaged components, and look for broken, bent, pushed, or corroded connector pins.

I’m an automatic transmission specialist, having this trouble code PO740 and the vehicle does not engage drive gear but when the valve body harness is unplug it goes drive, how do I go about?