Checked my truck for codes tonight using the key cycle function. The results were a code P0500 - Vechicle Speed Sensor and the companion P1693. The FSM for my '01.5 states the following about VSS:

Gas Engines and/or Diesel With Automatic Trans.
The Vehicle Speed Sensor (VSS) is no longer used
for any Dodge Truck.
Vehicle speed and distance covered are measured by
the Rear Wheel Speed Sensor. The sensor is mounted
to the rear axle. A signal is sent from this sensor to the
Controller Antilock Brake (CAB) computer. A signal is
then sent from the CAB to the Powertrain Control
Module (PCM) to determine vehicle speed and distance
covered. The PCM will then determine strategies for
speed control system operation.

What has me confused is my truck's speedo and odo still work just fine which would lead me to believe that the RWSS is working. So, does anyone have any insight into what is causing this code to be thrown? Should I go ahead and replace the RWSS?

 

Mine threw this code after driving thru a soupy mud puddle a few years ago. The ABS light came on so I kinda knew what happened. The code showed up when I ran the key cycle check and went away after a few weeks.

 

Usually throws this code from spinning the tires. And it usually goes away on its won. if not, you already know the sensor is on the rear diff - pull it off and make sure its intact.

In most cases the P-500 code is nothing to worry about.