4x4 fuel/power engine/tranny management question

[Kmvreter]

Curiousity question that came up in a conversation (about my 4th Gen V6 but could apply to any year or engine.)

Does Toyota have multiple or different fuel mapping and/or tranny shift point algorithms built into the ECU for when running in or out of 4x4 mode (or even 4Lo mode)? Basically, does the 4x4 mode have any input into the algorithms, the same as say engine coolant temps, or does the engine and tranny just adapt to the real time conditions and adjust via the constant learn mode?

 

[Robb235]

If I had to venture a guess, I would say "no". I'm thinking that the maps themselves remain unchanged, just that with being in 4wd there's more load on the engine, so the ECU sees this and references the fueling/timing maps accordingly.

That's just my guess, I don't really have anything to base it on.

 

[fourwd1]

One way to get an idea of yes or no would be to look at the wiring diagram and see if any signal from the 4WD/2WD selection circuitry makes its way back to the EFI ECM.
That may be more difficult on the newer vehicles where most signals are on a bus.