My new daily driver. 1984 dodge rampage

Yes, you unplug the temp switch to set base timing. Its like the electronic equivalent to disconnecting a vac advance on a distributor to set base timing.

The temp switch unplugged puts the computer into "block learn" mode. Then you can set the timing thru a slot cast into the trans bellhousing. The timing mark is on the torque converter, or flywheel on a stick.

With switch plugged in but in an open condition such as engine cold. The computer reads in "open loop" disregards the O2 sensor and allows the car to run rich because its cold. Once the temp switch closes the computer goes into "closed loop" and starts reading the O2 and other sensors in the system.