Symptom,

you can start the vehicle in park or nuetral, the instrument cluster displays the correct gear such as, P R N D,
when you Go from Park to Drive you can no longer go back into reverse, you need to switch of the ignition and then you can select reverse or park.

Testing

live data shows the error in which the ESM-Electronic selector module fails which position the gear selecting fails, there is 2 types of errors one where the selector is not selecting a gear type and the other where the CAN BUS signal is lost.
below you will find a video of the live data captured to know that the park position doesnot work after the fault has appeared you can no longer select reverse or park.

Repair and post testing

the same live data will be used to test the ESM-Electronic selector module switch that it now operates.