2010 ford flex ecoboost feels like drops into neutral

[Rodsmith]

 I have a 10 ford flex ecoboost I've owned it over five years now and it feels like it randomly drops into neutral and if I keep a foot on the pedal when Accelerating it makes a loud slamming noise. No check engine lights ever come on during, before or after.    Took it to dealer today , they test drove it with computer connected and did not get any codes.  Now what can I do? Any help will be really appreciated.    Thanks

[glock-coma]

You may want to check out the tsb section. There a few updates that are related to transmissions.
http://www.ecoboostperformanceforum.com/index.php?topic=496

[SHOdded]

Does it sound like TSB 10-9-9?
6F50/6F55 TRANSMISSION - DTC P0751 - HARSH OR NO FORWARD ENGAGEMENTS - PERCEIVED SLIP ON ACCELERATION - SLIP/DELAYED AND/OR HARSH DOWNSHIFTS

[66 Galaxie]

Could be a bad TRS (transmission range sensor).  There is a TSB on this as mentioned above.

[Brucelinc]

I agree with Galaxie.  My MKS did the same thing when it only had about 15,000 miles on it.  The dealer had a heck of time figuring it out because the service bulletin hadn't been issued yet.  There were no codes and they couldn't even confirm the issue.  After engaging the folks in Dearborn, they finally replaced the TRS and the transmission has been perfect ever since.  Later on a TSB was issued for this.

[jgb1234]

Yeah bro. I have the same issues with my flex,  for example, Im driving 45mph then suddenly it feels like tranny dropped into neutral and at the same time the reverse lights come on, or they will flash a few times. Also wanted to mention it will happen even if I have tranny in manual mode.

[66 Galaxie]

The flashing of the back up lights while having this issue also points to a bad TRS

[SHOdded]

TRS (Transmission Range Sensor) TSB 13-5-27
http://www.ecoboostperformanceforum.com/index.php/topic,496.msg23786.html#msg23786

[jgb1234]

FYI just have had the TRS replaced and it's been running great since. $696 and left it with the tech who drove it to and from work while having it connected to the computer. Finally it acted up and he found out the TRS failed. Replaced it and now I'm crossing my fingers the problem is solved.
Thank you guys all for the advise. I think yous were right on!

[Quinid]

Glad it acted up in front of the tech.  That ones an annoying one to get fixed.

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