Transmission Problems? Ask a Mechanic for Answers ASAP
Hi James, I'm Clay a certified master automobile technician with 30 years of automotive repair and diagnostic experience.
P0720 most commonly sets for the Output Speed Sensor (OSS) circuit. I'm not sure if you checked this circuit or simply threw a part at it. There are a couple different ways and a couple different places to check this circuit. Check the resistance of the OSS it should be(###) ###-####ohms. You can also verify the resistance at the PCM C2 connector on pins 25 and 28. Check also for an AC signal from the OSS with a voltmeter on the AC setting and the output shaft spinning, this will verify OSS operation and a loose or out-of-position reluctor on the transmission output shaft.
I hope this information is helpful. If you have any questions or run into any problems let me know.
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Hi James. I noticed you had viewed my answer, and I hope the information I gave was helpful. Let me know if you have followed through with my recommendations. If you have any questions, please let me know.
Positive ratings are greatly appreciated.Thanks so much.
Hi James, thanks for getting back to me. No problem, I had a pretty busy weekend myself. Using the diagram in the link below. Check the circuit from the PCM to the OSS sensor by disconnecting the negative battery terminal. Then disconnect the White C2 connector at the PCM, check the resistance between the terminals 25 and 28 and let me know how much resistance is on this circuit.
PCM Connector C2
If everything checks out electronically you may have internal transmission problem(s). With the transmission control relay removed will the transmission shift manually through all gears?
Let me knowThanks.
I'm going to opt-out and repost this question. Another expert may have more experience with this problem.Thanks.
Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.
Have you inspected the wiring fully leading from the transmission to the computer for any pinched,shorted or damaged wiring at all needing repaired or repalced?
Let me know so we can continue,thanks Pete.