Totally confused as to how to force a TCM relearn

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

Searching has left me more confused than anything else, so...

...How can a CRD be made to do a TCM relearn without a DRB-III or similar?

Pointers on this are most certainly appreciated.

ebbnflow · **Posted:** Fri Jun 05, 2020 4:45 pm

You need a quality scan tool to do a quicklearn on the trans. Drb3, autenginuity, micropod, snap on etc.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

ebbnflow wrote:

You need a quality scan tool to do a quicklearn on the trans. Drb3, autenginuity, micropod, snap on etc.

Thanks for the confirmation. I'll add it to the 'next time I go somewhere that has better scan tools than I do...' list.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

casm wrote:

ebbnflow wrote:

You need a quality scan tool to do a quicklearn on the trans. Drb3, autenginuity, micropod, snap on etc.

Thanks for the confirmation. I'll add it to the 'next time I go somewhere that has better scan tools than I do...' list.

Can you explain what the quick learn even is? I’ve read conflicting info on were the tcm even learns at all. And why would it need to anyway?

WWDiesel · **Posted:** Sun Jun 07, 2020 2:43 pm

Jett wrote:

Can you explain what the quick learn even is? I’ve read conflicting info on were the tcm even learns at all. And why would it need to anyway?

Read all about it:
The RFE transmissions TCM's have a drive learn procedure that allows the TCM to fine tune individual shifts such as N-D engagement feel. This feature allows individual shifts schedules to be fine tuned.
Important to note; If the shift linkage is out of adjustment causing the range sensor to feed back transitional signals to the module you will have erratic shift concerns that will not set a code and cause shift concerns. When in OD it must read OD on the scan parameter and not a temporary (T3 or T4) parameter.

More:
Unfortunately, there is no easy trick to do a quick learn procedure without the proper tools. You will have to take it to a dealership, or a good transmission shop that have the proper equipment like the DRBIII or a Snap-On Verus Pro or another very high end scanner to have it performed. A DRBIII or Snap-On tool can be anywhere from $5000-up to purchase new, and requires a good bit of training and experience to use one properly.

What exactly is a quick learn procedure and what does it actually do! :
Your 545RFE transmission uses the thickness of all the clutches inside as values. this tells the transmissions computer how and when to shift. So when a transmission goes bad, the clutches are usually very thin, and the transmission uses those values and compensates for them in the shifts. when you replace the transmission with a new or rebuilt unit, the computer TCM will still use the old values of the previous transmission it had learned. so the TCM still thinks it has very thin worn clutches, but it actually has brand new thicker ones. this can cause excess wear or slippage in your new transmission parts, thus the need for the quick learn.
The quick learn procedure is performed while driving at various speeds, and it allows the transmission to relearn all the the clutch thickness values (CVI numbers) and then process them into how and when to shift using those newly learned values.

Is it possible to get away without doing one, yes, but it certainly is NOT recommended or advisable!
You certainly don't HAVE to have the Quick Learn Procedure performed. but if you don't you risk putting a new or newly rebuilt transmission through excess wear and tear....

To read actual TCM Quick Learn Procedure from the Transmission FSM, click on this link and then go to page 2 starting at 3.2.3
3.2.3 DRIVE LEARN PROCEDURE – 45/545RFE

Totally confused as to how to force a TCM relearn

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