Auto transmission problem- Hyundai Accent GLS 2001

Take a look at the shift solenoid...

Could be, and you'll be lucky if that's all it is. Joemom, by solenoid, are you referring to the "speed sensor "? I had this go out on my old 95 Honda Accord. If it's not, then, this is a classic symptom of a worn out transmission and you will need an overhaul. Good luck.

thanks to you Joemom & Markw, when I show this to one technician, he said need to replace the Valve Box, but that also not sure to him as whether problem is solving after that, meanwhile pls advise, the Solenoid is means same as the Valve Box,

This may sound unrelated but check to see if you have a bad set of spark plug wires .if you do here's what's going on .at idle with a closed loop ecm your KV load on the ignition is pretty low general speaking. Once the cars in drive it may or may not have enough load to miss fire! in the instance of these accents usually not ,but when you step on the gas the bad wire shorts to ground and all the sudden its a "two cylinder " these cars have what's called a waist spark ignition. whch means each coil fires terminal to terminal .pole to pole, if the output side of the circuit is the culprit you loose not one but both cylinders and .8Liters is not enough to get out of its own way. I know you think I'm nuts but take a look

The same problem with Hyundai accent 1.6 diesel year 2013 https://www.rentpoint.al