Transmission loses track of its gear

[calling_john_galt]

I have a 2015 Edge SE with the 3.5L engine, 56k miles. I have an intermittent problem where while driving at operating temperature, the following happens:

 

1. Transmission slips out of gear.  It tries to get back into gear, resulting in lurching.  Engine continues to run.

2. The gear indicator in the instrument cluster does not display the gear the shifter is in (see attached pic, note the tach shows the car is running, just no gear indicated.)

3. The rear camera activates.

 

The only solution is to stop the car, put it into park (still without a gear indicator displaying on the instrument cluster), stop the engine and start over.  Until recently this has resolved the problem.  Most recently, the problem immediately recurred.  On the 8th try, it cleared up.

 

No codes captured, no error messages displayed.  Have never seen the "Shift-to-park" error since we've owned the car.

 

Been to the dealer twice, but of course they are unable to reproduce.  They did confirm that there were no codes of any kind captured.

 

Any suggestions on things to look at?  

 

Thanks for the help!

[calling_john_galt]

It finally happened while I was driving.  I first noticed the rear camera was on while at highway speeds.  Then I noticed the gear indicator.  The transmission made no attempt to go back into gear-- it just coasted about 3-4 seconds.  Then the camera turned off and it went back into gear as if nothing happened.

[Will W]

This happens off and on with our 2015 Ford Edge.....  very unsafe if will happen at any speed.   I have videos of it going in and our of gear.  Wish Ford would send a computer update and/or recall for this before someone get in a serious accident or killed.  

[1004ron]

1 minute ago, Will W said:

This happens off and on with our 2015 Ford Edge.....  very unsafe if will happen at any speed.   I have videos of it going in and our of gear.  Wish Ford would send a computer update and/or recall for this before someone get in a serious accident or killed.  

 

Welcome.

 

What's the mileage and service history?

 

Have you done any maintenance on the transmission, such as a fluid replacement?

 

Did you take it to Ford for them to diagnose it and quote on repairs if needed?

[Home Fix]

I have the same issue with my 2015 3.5 Edge SEL.

calling_john_galt & Will W --- did you ever get this resolved? If so, how?

 

1004ron --- I notice approximately 3 months after doing some work on it.

Changed water pump, timing chain & guides and drained & filled transmission at about 110K miles (2 years ago). Now have 147K on it and it still does this intermittently.

 

Does anyone know what special tools are needed and any links to video so I can see what I am getting myself into?

 

Thanks!!!

[enigma-2]

I may have found the fix in the F150 forum, where they have seen simular problems.

 

The cause of the problem is most likely a failing Transmission Range Sensor.

 

When your Edge reaches operating temperature, heat expansion causes an electrical open circuit or glitch inside the sensor. The TRS completely loses track of what gear the car is in, which triggers all three of your symptoms simultaneously.

 

The symptoms may feel like they are separate issues, but they are all tied to this particular sensor.

 

The PCM uses the signal from  the TRS to know which gear is selected.  Because the PCM is getting blank or corrupted data from the TRS, it cannot output a gear position (P, R, N, D, S) to the digital instrument cluster.

 

Also, when the TRS signal drops out while you're driving, the PCM gets confused and drops hydraulic pressure which causes the transmission to slip out of gear. If the TRS starts working again, it generates a signal the the PCM and the PCM will attempt to re-engage the transmission. This will cause  lurching).

 

The reason the rear camera activates is when the TRS is corrupted, its outputting a false reverse gear signal, which causes the BCM to believe that the transmission is in reverse;  and turn on the backup camera display.

 

The reason the dealer didn't find any codes is probably due to, when the 6F50/6F55 TRS faults, is usually doesn't set a "permanent" code, such as a  P0705 or similar. The code it dies set, is reset when you cycle the key. By the time you drive it to the dealer and they scan it, the system doesn't retain a code.

 

Since the dealer cannot reproduce it, you need to alert them to this possibility and tell them that you suspect an intermittent internal "Transmission Range Sensor / Leadframe" fault that occurs only at operating temperature.

 

The technician will need to drive the car with a factory scan tool hooked up, specifically monitoring the "TR_D" (Transmission Range Desired) and "TR_A" (Transmission Range Actual) PIDs. They'll watch for the signal to drop or turn to eith Fault or Unknown when the vehicle gets hot. (Make certain when you take it in you have a full tank of gas as it may have to be driven many miles before the test begins. Or before the module faults.)

 

You can also record a video the next time this happens. Showing this video to the  service manager bypasses the "cannot reproduce" problem.

 

.

 

Edited 1 hour ago by enigma-2
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