2002 Dodge Durango 5.9L Engine Code P0720: Intermittent Second Gear Sticking Issue
New to the forum. I'm experiencing an intermittent second gear shifting problem with my 2002 Dodge Durango 5.9L V8. The vehicle will randomly fail to shift out of second gear—sometimes driving 30-40 miles without issue, but after stopping and restarting from a station, it won't shift properly at speeds between 35-40 mph, with RPMs remaining high. I've already replaced the transmission fluid, both output speed sensors, the governor pressure solenoid (OSS), the OSS sensor/transducer, and the coolant temperature sensor. Despite these repairs, the P0720 diagnostic code persists. I'm at a loss as to what might be causing this issue. Any insights or suggestions on potential causes—especially related to wiring, sensor grounding, or communication between the PCM and output speed sensors? Thanks in advance for any help.
Replaced the governor pressure solenoid (OSS) using ATF-4 fluid. No new codes appeared, but P0720 remains. This suggests a wiring issue with the OSS—common fault points include intermittent connections or damaged harnesses. Possible failure modes: - Intermittent wiring and connectors - Output speed sensor ground circuit open - Output speed sensor signal circuit open - Output speed sensor ground circuit short to ground - Output speed sensor signal circuit short to ground - Output speed sensor ground circuit short to voltage - Output speed sensor signal circuit short to voltage - Output speed sensor (general fault) - PCM communication issue with output speed sensor