Quick Question.

Dealer had to replace the battery because truck sat on lot for a while and would not charge.

BUT. I don't think they sent thru the re-learn process of the PCM afterwards.

So, I am familiar with the process from reading on here.

The question is....

When its learning the idle values, should I be doing this from a cold engine, or with it partially warmed up

the 5.0 in the 18's idles high cold and takes forever to go into low idle. should it be learning thru this long warm up/idle time, or should I just warm the engine up a bit, then disconnect the battery again for 30 minutes, and let the relearn start with a warmer engine?

Does it make a difference learning idles cold or warm?

Truck just shifts weird and takes forever to go into low idle (so, could this be the result of the PCM relearn not being done correct when the dealer changed the battery, or do these 5.0's just take forever to idle down)

Just want to make sure I do the process/relearn properly and not have to do it again.

Thanks!
Greg

 

Does the Battery Monitoring System (BMS) still exist on 18's? I didn't see any of the "rings" around the cables or any connector one might unplug.

 

When a PCM re-learn is done, it is done from a cold started engine, to fully warm.

 

Absolutely, it's a requirement of ***. In later years, the sensor is built into the battery clamp.

 

I was about to say they changed the battery cable and attachment but BCM is still there. And it's on ALL MODELS now. So any 2018 model will have it. Used to be some of the non start stup, lower tier models without infotainment etc wouldn't have it (like a XL base) but as far as I know they all have it now.

 

Performed the re-learn procedure today step by step. Much smoother shifting now after about 30 miles.

If your 18 5.0 with the 10 speed shifts like ****, do the re-learn

 

Did you buy it new and had a dead battery from sitting? If so the computer had nothing to re-learn since it was new and never driven. The transmission's adaptive learning is the computer learning how the owner drives and adjusts it's shifting strategy for the owner's driving style. The shifting strategy of a new truck is the base programming before adaptive learning makes changes. The re-learn clears the adaptive shifting strategy and returns the computer to its default programming from the factory.

 

It had 90 miles.