10R80 issues - P0C29

[NorCal Offroad]

I love this truck. HATE this transmission. When its good, its great, but thats not very often.
Used to hang and bang into gear when cold, thats subsided after a couple fluid changes (not flush), but still flares a bit in some gears (2-3, 4-5, 6-7, 9-10 is bad). Lately the most concerning thing is 3rd gear slipping. Seems if I'm in 3rd getting on the highway, give it more than half throttle, it slips, goes to redline, hunts around gears, until it drops into 5th, and then I'm able to continue. This makes merging onto busy highways really not fun. No codes on my Accessport, but hooked up Forscan today, and have DTC P0C29 set. Search says this is the Aux trans fluid pump which is for auto start/stop. I have auto start/stop disabled - could this be related to my issue? Or am I looking at valve body/CDF problems? TCM has @GooseTuned tune. Will work on getting a video this afternoon.

VIDEO

 

[smurfslayer]

I have had auto stop start disabled since I upgrade the stereo back in .... 2019? Have never seen this code (or had these symptoms).

 

[NorCal Offroad]

link to symptom video added, will try to get a better video of the 3rd gear slip later on

 

[GooseTuned]

link to symptom video added, will try to get a better video of the 3rd gear slip later on

Have you checked your fluids?

The trans shouldn’t do that. That’s definitely a mechanical problem

 

[NorCal Offroad]

@GooseTuned I know it’s in range but I’ve never seen it run that hot just driving around, even driving like that. Going to check fluids tomorrow. Trying to determine valve body vs cdf, haven’t been successful in finding symptoms for valve body failure. I can occasionally hear a loud click on shifting which is making me thing valve body

 

[julien194b]

several oil change for how many miles ? Are you sure about quantity and type of fluid you put in !
To do a serious trans fluid flush, follow this:

Transmission Fluid - Concencus?

Wondering what the concensus is on transmission fluid / filter changes on this truck. I am back in a raptor from a cummins high output where I was changing fluid every 30K and fluid / filter every 60K. Given there is no dip stick on this truck and I have read multiple folks stating to "never...

www.fordraptorforum.com

I admit we need a special engenering formation to read correctly the dipstick

 

[NorCal Offroad]

Changed the pan/filter and refilled at 78k. Fluid was black. Changed it again at about 81k because obviously I didn’t get everything out just by draining and filling. This improved the shifting a lot, but still not perfect and now having new, different issues. Using Valvoline ULV. @FordTechOne says don’t flush the trans.

 

[Donovan]

Subscribed.

My goal in the future is to do a full trans kit rebuild and then go Goosed.

 

[GooseTuned]

Changed the pan/filter and refilled at 78k. Fluid was black. Changed it again at about 81k because obviously I didn’t get everything out just by draining and filling. This improved the shifting a lot, but still not perfect and now having new, different issues. Using Valvoline ULV. @FordTechOne says don’t flush the trans.

Shoot me an email in our tuning thread please

 

[NorCal Offroad]

Shoot me an email in our tuning thread please

Done