2010 Yukon 6l80 slow to engage Drive and Reverse

[new to yukon]

Hey, new to TYF. I have a 2010 Yukon, 220K, recently flushed and replaced fluid/filter as well as installing replacement Delco check valve balls and plate. Previously the transmission was flaring (as near as I can tell, I'm not even an amateur) in several gears and was taking a long time to engage Drive or Reverse after warming up (not really drivable either, had it towed home after this started happening). I'm told I need to relearn the clutch shift details (at least 'fast' learn?) after replacing the fluid/filter - is this true? My Autel scanner does not appear to have access to a learn function in any of the diag menus, I'm not sure how to determine if my TCM can even do this on a 2010. Some other details:

1) the Gear ratio value is colored red, rather than black, when read by my scanner and is 8 (not sure what it's supposed to be, but the displayed range in parentheses has a maximum of 5)
2) the TCC Pressure control solenoid pressure command always reads 'NO' with a value of zero kPA in live data, regardless of whether the transmission is in P/N/D; I thought the value was 100 prior to changing the fluid/filter.

Also, there are no error codes being thrown.

Please let me know if I can provide any other troubleshooting details and thanks for all of the information on this forum...

 

[Geotrash]

Hey, new to TYF. I have a 2010 Yukon, 220K, recently flushed and replaced fluid/filter as well as installing replacement Delco check valve balls and plate. Previously the transmission was flaring (as near as I can tell, I'm not even an amateur) in several gears and was taking a long time to engage Drive or Reverse after warming up (not really drivable either, had it towed home after this started happening). I'm told I need to relearn the clutch shift details (at least 'fast' learn?) after replacing the fluid/filter - is this true? My Autel scanner does not appear to have access to a learn function in any of the diag menus, I'm not sure how to determine if my TCM can even do this on a 2010. Some other details:

1) the Gear ratio value is colored red, rather than black, when read by my scanner and is 8 (not sure what it's supposed to be, but the displayed range in parentheses has a maximum of 5)
2) the TCC Pressure control solenoid pressure command always reads 'NO' with a value of zero kPA in live data, regardless of whether the transmission is in P/N/D; I thought the value was 100 prior to changing the fluid/filter.

Also, there are no error codes being thrown.

Please let me know if I can provide any other troubleshooting details and thanks for all of the information on this forum...

Start here and see if this thread has what you need: https://www.tahoeyukonforum.com/threads/gm-6l80-transmission-information-thread.141927/

 

[new to yukon]

Start here and see if this thread has what you need: https://www.tahoeyukonforum.com/threads/gm-6l80-transmission-information-thread.141927/

Thanks @Geotrash, I'll drain it and pull the pan/TEHCM to check all the solenoids per that thread link. Much appreciated, I'll post here with what I find?

 

[Joseph Garcia]

@NickTransmissions

 

[NickTransmissions]

Hey, new to TYF. I have a 2010 Yukon, 220K, recently flushed and replaced fluid/filter as well as installing replacement Delco check valve balls and plate. Previously the transmission was flaring (as near as I can tell, I'm not even an amateur) in several gears and was taking a long time to engage Drive or Reverse after warming up (not really drivable either, had it towed home after this started happening). I'm told I need to relearn the clutch shift details (at least 'fast' learn?) after replacing the fluid/filter - is this true? My Autel scanner does not appear to have access to a learn function in any of the diag menus, I'm not sure how to determine if my TCM can even do this on a 2010. Some other details:

1) the Gear ratio value is colored red, rather than black, when read by my scanner and is 8 (not sure what it's supposed to be, but the displayed range in parentheses has a maximum of 5)
2) the TCC Pressure control solenoid pressure command always reads 'NO' with a value of zero kPA in live data, regardless of whether the transmission is in P/N/D; I thought the value was 100 prior to changing the fluid/filter.

Also, there are no error codes being thrown.

Please let me know if I can provide any other troubleshooting details and thanks for all of the information on this forum...

Drop the pan and inspect the bottom...My guess, based on mileage and symptoms, is that it's time for a complete and total overhaul but you wont know for sure until you get the pan off and have a look-see.

 

[donjetman]

Also
https://www.tahoeyukonforum.com/threads/transmission-codes-p0842-p0872-p0877-update.145047/