Aisin Transmission Service → Throws P0868 code

[PacificNorthwestRVers]

Yesterday I serviced the Aisin transmission in my 2019 Ram 3500 HO; changing the fluid. pan gasket and filter. I carefully measured the old Mobil 3309 ATF (8 qts 1.5 pts) and installed the same amount. After a minute or so of idling, I shifted back and forth between Park/Neutral and Drive/Reverse. the N→D and N→R shifts were brutally hard. Several minutes later, we drove it off the ramps and off on a road test. The shifts continued to be severe for about 1/2 mile, when they returned to normal.

However, the Check Engine light came on. The scan tool showed P0868. The code & light persisted after numerous on/off cycles. It was time to watch Sunday's NASCAR Cup race. Several hours later, I restarted the Ram, cleared the code, and drove about 10 miles. While the transmission behaved normally, the P0868 code persisted after repeated clearing.

Suggestions?

 

[Ozymandias]

No idea but that code combined with Aisin is all over Google, seems to be a frequent problem.

 

[sag2]

Are you sure the filter is installed correctly? If all you did was change the fluid and filter I suspect it was something you broke in the process. Star Online cases show connector (unlikely as you didn't touch it), valve body (unlikely as you didn't touch it), front pump gasket (unlikely as you didn't touch it).
Most of the direction is to transmission harness and transmission harness connector behind driver wheel. Again, unlikely as you only dropped the pan.

 

[PacificNorthwestRVers]

Are you sure the filter is installed correctly? If all you did was change the fluid and filter I suspect it was something you broke in the process. Star Online cases show connector (unlikely as you didn't touch it), valve body (unlikely as you didn't touch it), front pump gasket (unlikely as you didn't touch it).
Most of the direction is to transmission harness and transmission harness connector behind driver wheel. Again, unlikely as you only dropped the pan.

Anything is possible. However, as you noted, all I did was drain the ATF, lower the pan, remove the 3 bolts retaining the filter. drain that ATF, install the new filter, and reinstall the pan. Nothing along the way fought me in any way; it's a simple job albeit a bit messy.

 

[PacificNorthwestRVers]

No idea but that code combined with Aisin is all over Google, seems to be a frequent problem.

Quite true, although the preponderance of Google leads involved things that I never touched.

 

[sag2]

Anything is possible. However, as you noted, all I did was drain the ATF, lower the pan, remove the 3 bolts retaining the filter. drain that ATF, install the new filter, and reinstall the pan. Nothing along the way fought me in any way; it's a simple job albeit a bit messy.

Are you sure the filter O'ring is installed correctly?

 

[PacificNorthwestRVers]

Are you sure the filter O'ring is installed correctly?

It's difficult to say for certain at this point. I did lube it with ATF before installing the filter, and it seemed to snap in OK. I'm seriously considering taking it back down tomorrow.

 

[sag2]

To minimize the mess, stop at HD or Lowes and get a mortar mixing tub. Usually less than $10 and they work great.

 

[PacificNorthwestRVers]

To minimize the mess, stop at HD or Lowes and get a mortar mixing tub. Usually less than $10 and they work great.

Thanks, I'll have to check that out. Historically, a kitchen trash can full of GreaseSweep (aka Kitty Litter) has been my go-to method for decades.

 

[Diesel85]

To minimize the mess, stop at HD or Lowes and get a mortar mixing tub. Usually less than $10 and they work great.

And put some cardboard down to catch any splatter.

 

[PacificNorthwestRVers]

And put some cardboard down to catch any splatter.

Yeah, I have a large piece of cardboard for that, however the creeper and the cardboard don't talk nicely to each other.

 

[PacificNorthwestRVers]

Hmm. Drained the oil, pulled the pan & filter. Found nothing amiss. The filter was in place and well engaged in the housing, and all the wiring connections secure and none out of place or pinched.

 

[Cummins12V98]

No problem with mess if you drain overnight then remove pan and filter.

 

[PacificNorthwestRVers]

No problem with mess if you drain overnight then remove pan and filter.

That's what I did originally for exactly that reason. However, when I fired it up this morning, got a code, cleared it and immediately got the code again, I simply drove it onto the ramps and pulled the plug, had breakfast and then pulled the pan. Yeah, made a bit of a mess.

On reassembly, I made sure to push/snap the trans filter into the trans before torqueing the bolts. Found a thread on another forum that noted that as a fix. Hopefully, that'll work for mine.

 

[PacificNorthwestRVers]

OK, snapping the filter into the transmission by pushing up firmly under the filter was the trick. Once again, it spit out the P0868 code enough to trip the CEL and create a permanent code as well as shifting harshly for a while even after over 10 minutes of idling before shifting out of N. But, after a few minutes on the road it shifted smoothly, stopped throwing the P0868 code. After a few restarts, the CEL and permanent code went away.

I need to find a funnel that fits the transmission dipstick tube tightly so it doesn't leak and drip while filling.

 

[Ozymandias]

Excellent, good to know.

 

[NonFord]

When I first did mine, it had a fit on initial startup too. However, letting it idle for a few minutes and after like 3 key cycles the code went away. My belief is to let it build up pressure and flow through before putting it in gear. I've done this two times again without incident!

 

[rynosback]

Mine through the same code. I reset the code and it has not come back. So it was just for that brief moment of low pressure when start up after the service.

 

[bcbender]

Unfortunately I had the same code last night. I did everything as noted and followed in torque / process laid out in issue 94 but still got the code. Reset it with scan tool and it was fine, same symptoms as others, hard gear engagement P-R-N-D-R-P... must be a luck of the draw thing, I am going to drive it today, confirm the level and roll on!... Strange it sets a Permanent Code since it is not a persistence or repeated condition.

 

[Cummins12V98]

After filling it with same amount you drained when you started it did you high idle for a bit before changing gears? Did you go from Park to Neutral at first shift?

OH and most important did you hold your tongue just right???