Something I failed to mention, and I think it's important, is that the code is generated while the vehicle is running and standing still. If I turn the key on but don't crank the engine, clear the codes, turn the key off, turn the key back on (without starting) and connect the scanner, there is no P0500 code. However, if clear the codes, turn the key off, crank the engine - but don't even take it out of "Park", and connect the scanner, I have the P0500 code show up. I read something that said a bad alternator rectifier could cause AC current in the system that confuses the VSS circuits. It seems to me that there are 3 possible issues.
1. An open circuit is detected when not expected. (Broken wire, bad connector, failed sensor)
2. A short is detected. (Less than expected resistance - damaged insulation, failed sensor, stuck relay)
3. Something thinks the truck is moving when it isn't.
Since there are no symptoms, I'd be tempted to ignore the code. BUT, my vehicle inspection/registration is due in Collin County, Texas and I'm pretty sure the P1000 code is going to fail inspection.
Is there an easy way to check the alternator rectifiers without an oscilloscope or physical tear-down?