To let the PCM know that the engine is warm enough for closed loop mode.
No, there is no "adjustment".
Powertrain Control Module
Timing is set by the PCM and is not adjustable.
Timing is set by the PCM and is not adjustable.
No, the speedometer is driven electrically from the PCM.
Timing is set by the PCM and is not adjustable.
Unhook the battery for a minute to reset the PCM.
Idle speed is set by the PCM and IS NOT ADJUSTABLE.
PCM, TCM, and internal transmission mechanicals.
Timing is set by the PCM and not adjustable.
There is no such device on a '97 villager.