2021 RAM With 68RFE - PI Curve Relearn?

[Jwaller]

Hello, I own a 2021 RAM with a 68RFE.

Since tuning (EFi live with a Canadian vendor) and relearning, the 1-2 and 2-3 shifts feel like they grab the shift, but only sometimes.

It’s worst when the trans is cold or at full operating temp (168f), and the shifts are smoothest at 15-20% throttle and trans temps at (130-150f)

I have AlfaOBD and can do a transmission relearn.

Can I perform the relearn, and should this suffice to reset all the CVI values?

Someone in the forums (Chrisn?) mentioned he is a dealer tech and that a pi curve relearn must be done on the 5th Gen 68RFE.

I recently went to my dealer to have a couple of recalls done, and the service writer told me they had to flash my truck in order to perform a relearn.

They are cool with the truck breathing well, but the warranty is questionable as I don’t know what hoops they must jump through with FCA before the warranty work.

Is there any way to do a pi curve relearn post aftermarket tuning without going to a dealer, or can the dealer do a relearn without erasing my tuning?

Please tell me what a PI curve relearn is and if I need it.

Thanks!


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[Chrisn162001]

You don’t need to relearn the pi curve unless you swap valve bodies or the complete transmission.

A normal, quick learn should be good.

If not, the tune is likely the issue.


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[Jwaller]

Thank you!

You are the guy I was hoping would reply!

I will perform the quick learn today.

To make sure I’m going to do this right:

1. Get trans to operating temp.

2. With the truck running, the e-brake is on, cover the brake, and on a level surface, initiate the relearn.

Follow prompts:

3. Exhaust brake off driving at <30% throttle in stop-and-go conditions for at least 30 miles.

Should I start out at 5% throttle through the lower gears until they smooth out and slowly get into a higher throttle and higher gears?

Or drive it <30% throttle?


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[Chrisn162001]

Thank you!

You are the guy I was hoping would reply!

I will perform the quick learn today.

To make sure I’m going to do this right:

1. Get trans to operating temp.

2. With the truck running, the e-brake is on, cover the brake, and on a level surface, initiate the relearn.

Follow prompts:

3. Exhaust brake off driving at <30% throttle in stop-and-go conditions for at least 30 miles.

Should I start out at 5% throttle through the lower gears until they smooth out and slowly get into a higher throttle and higher gears?

Or drive it <30% throttle?

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Drive it normally under 50 percent throttle.

No exhaust brake is best.

The quick learn gets the baseline pretty close.

Driving fine-tunes it.


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[Jwaller]

I appreciate you!

I’ve loaded several tune revisions, and every time during the relearn, it would throw a P0765 code (UD solenoid fault).

Well, it threw the code about a year ago; I cleared it and drove it.

It’s just had that weird shift that has weighed on me, but I’ve been nervous to do anything about it as I don’t want to deal with going into limp mode and messing with the tune again.


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[Jwaller]

Can anyone tell me which transmission ECU function I should connect to with a 2021 68RFE?




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[AK Bob]

Can anyone tell me which transmission ECU function I should connect to with a 2021 68RFE?

https://uploads.tapatalk-cdn.com/202...3146013240.jpg


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I would navigate to this page and select the highlighted (see attached), then click on the “Active Diagnostic” tab, and in the top drop-down menu, scroll down to “Quick Learn (PCM RFE Transmission).”

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[Jwaller]

I would navigate to this page and select the highlighted (see attached), then click on the “Active Diagnostic” tab, and in the top drop-down menu, scroll down to “Quick Learn (PCM RFE Transmission).”

Do I need to have the OBD link application open to see those options?

I don’t even get an option for that! I still have the bypass cable wired into the OBD2, so that shouldn’t be an issue.


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[Jwaller]

Ok!

I finally cleared it after connecting the first time; it failed to relearn for a P2701 fault.

Cleared it, then it took.

About to drive it now.

Thanks, AK and Chrisn!


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[AK Bob]

Do I need to have the OBD link application open to see those options?

I don’t even get an option for that! I still have the bypass cable wired into the OBD2, so that shouldn’t be an issue.


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Ok!

I finally cleared it after connecting the first time; it failed to relearn for a P2701 fault.

Cleared it, then it took.

About to drive it now.

Thanks, AK and Chrisn!


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I'm glad you figured it out; you need to be in the “Engine” function.

Hopefully, the relearn will take care of the issue, and please keep us posted.

Attached is the troubleshooting information for your trouble code for reference.

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