1999 Dodge 1500 5.9L Engine Code P0720: Possible Rear Axle Sensor Issue?
I'm working on a 1999 Dodge 1500 with a 5.9L V8 engine and automatic rear-wheel-drive setup. The vehicle is throwing Diagnostic Trouble Code P0720, indicating a malfunction in the transmission input speed sensor. I recently replaced the transmission speed sensor, but after driving the truck, the check engine light returned and the same code (P0720) reappeared. Could there be a rear axle speed sensor or another related component causing this issue? Are there any other sensors or systems that could trigger P0720 in this model?
The key point here is a CIRCUIT malfunction—this suggests the issue may not be with the sensor itself, but rather with wiring, grounding, or signal integrity between components.