So I have a 2006 mustang 4.0 v6 automatic, getting code p0720( output speed sensor ) I replaced it and it comes back . O/D light flash and speedometer don’t work . I tested resistance to all the sensors on the transmission (input , turbine Output speed sensor) all was good also checked harness not damaged has power and ground . I’m lost on what to do , could it be the TCM, the 6r80 transmission had the same issue and it’s the TCM lead frame which the 5r55s transmission doesn’t have (2005-2009) transmissions. Seems to be a common problem with the 2005-2009 mustangs have anyone had this issue?

 

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