2010 Yukon 6l80 slow to engage Drive and Reverse

new to yukon said:

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...

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Geotrash said:

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

Click to expand...

new to yukon said:

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...

Click to expand...