Smart thermostats and pumps are adding a new wrinkle to diagnostics.
A conventional thermostat and water pump are similar to a carburetor and mechanical fuel pump in one regard — they can only respond to change, not be proactive in their engine management.
A carburetor and mechanical pump can only respond to throttle and engine speed and vacuum signals. Like the carburetor, a conventional thermostat and water pump can only react to changes in temperature.
Click HERE for the rest of Andrew Markel’s article from Underhood Service.