A 2001 5-door Tracker has three keyed lock cylinders and one lock switch on the driver's door armrest.
Only one door at a time can be unlocked manually using a key but all the doors can be locked electrically at once from any door using the same key.
Here's how that's possible.

Each of the five doors has a lock solenoid (designated "M" above). Any time 12 volts is applied to the tops of
the solenoids all the doors will lock. To get 12 volts from the 20-amp door lock fuse to the solenoids the relay
coil of the door lock relay must energize. The top of the coil is permanently connected to ground. When 12
volts finds its way to the bottom of the coil, the coil energizes, the normally-open contact inside the relay closes,
the door solenoids energize and all the doors lock at the same time. Each mechanical door lock cylinder has
a normally-open switch attached to it. The three cylinder lock switches and the interior lock switch are connected
in parallel. When any one of the switches is closed the door lock relay energizes and all the doors lock at once.

 

If your 2001 5-door Tracker also has keyless entry the circuit above is incorporated into the keyless entry schematic below.

The green lines are permanent grounds and the red lines are always 12 volts. The black lines change states as required. As before, 12 volts supplied to the tops of
the solenoids ("M") locks all the doors at one time. In this circuit 12 volts applied to the bottom of the solenoids unlocks them. It takes two clicks of the unlock button
on the key fob to open all five doors. However, it only takes one press of the interior door lock switch to open all five doors. Here's how that works. When the door
lock rocker switch is pushed to the unlock position, 12 volts is applied to the top of the unlock relay coil. The relay energizes, the normally-open contact closes,
12 volts is passed to four of the five door lock solenoids. Simultaneously the rocker switch sends a 12 volt unlock signal to pin "B" of the keyless entry module.
In response to the unlock signal the keyless module flips the transistor switch at pin "A" to the (12 volt) battery position. Pin "A" then supplies 12 volts to the bottom
of the driver's door lock solenoid causing it to unlock. The answer to this next question has no practical value but which doors unlock first?

The Tracker lock and unlock relays are both Omron G8H micro ISO style relays. Including the bounce time, it takes 25 milliseconds
for the mechanical relay contacts to close. In contrast, the solid-state transistor switch at pin "A" operates in microseconds (a thousand
times faster). Even taking into account the time it takes for the logic functions to route the signal from pin "B" to pin "A", I suspect the
driver's door lock motor gets its unlock voltage the tiniest bit faster than the other four.