2014 Hyundai Accent transmission issue

My car is automatic transmission. when i put it in D it has knock and move with only one speed no change from speed to another also speedometer not work. when we check it with diagnosing tools it read out put speed sensor have no reading, we change it but the problem still sxist

When there are symptoms of a bad transmission speed sensor , the powertrain control module cannot control the shifting of gears within the transmission properly. This may cause transmission revs higher before shifting gear or leading late transmission overdrive and inability to go into that top gear. Harsh shifting may damage internal components such as valve bodies, hydraulic lines, and even mechanical gears in some cases.

Go to a transmission shop to get a proper diagnostic.

The vehicle speed sensor function has to work for the transmission to shift properly. Its output is usually a repetitive electronic pulse who’s frequency increases with vehicle speed. Your replacement sensor may be faulty, or the thing that it senses inside the transmission may be faulty or mis-aligned with the sensor, there may be a problem with the wiring between the sensor and the computer that reads its output signal, and there may be a problem with the computer itself. As posted above, this is probably going to require a Hyundai specialist shop, or a transmission shop to properly diagnose.