dockmasterdave

I have an 06 F 150 with the 4.2 and 86,000 miles. The transmission has been shuddering on the 1 to 2 shift when pulling a trailer. I checked the OBD2 codes and got an P1900 which shows as trans output shaft speed sensor faulty. I also got a P1500 which doesn't seem to show up anywhere. I know it's a trans sensor but don't know which one. I'm wondering if need a new transmission or if it could be one of the faulty sensors causing the shudder?
Any one know what this code is. Thank you in advance for your input.
P.S. Brand new to this forum, curious to see the responses.