Transmission will not shift out of first gear

2012 FORD F-150
158,000 MILES • 3.5L • 6 CYL • TURBO • 4WD • AUTOMATIC
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F150ECOBOOST
  • MEMBER
  • 4 POSTS
Took off this morning and the truck wouldn't shift out of first gear. RPMs went to about 3500. I took my foot of gas and RPMs jumped up a little and came back down slowly, but still would not shift out of first gear. Noticed speedometer not working. After about a minute it started working again and worked fine. It did the same thing after work.

Does this sound like throttle positions sensor, or speed sensor, or something else?
Jun 27, 2022 at 9:37 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,647 POSTS
The speedometer and transmission depend on the speed input from the ABS and body control modules. To find out which one is bad let's do a CAN scan which is the future of automotive repair. You can get a CAN scanner from Amazon for about $30.00. here is a video to show you how and a link to a scanner from Amazon. I have included how to change out the BCM, which is what I think is bad.

https://youtu.be/u-4syLc-ifQ

and

https://amzn.to/3OpAotj for the scanner

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

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Jun 28, 2022 at 3:40 AM
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F150ECOBOOST
  • MEMBER
  • 4 POSTS
It was the transmission speed sensor, or lead frame sensor in this particular transmission. $1,000. fix.
Jul 11, 2022 at 8:44 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,647 POSTS
yep, good find, sorry it cost so much. Use 2CarPros anytime, we are here to help. Please tell a friend.
Jul 12, 2022 at 3:52 AM
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