No reverse on 2000 Exploder

2002 Explorer XLS V6. 149k miles.

We lost the reverse gear. Transmission fluid is normal, no leaks, it drives and shifts fine in drive. According to the driver (wife) when she selects reverse, the truck shifts itself into drive. I believe its the 5r55n transmission.

Thanks

if other gears work,,,,most likely low/reverse band is broken