Re: 2.0TS Cold Idling
the rpm depends on the coolant temperature, there is a graph in the manual that shows the relationship between temp and rpm.
this time of year it should be 1250-1350rpm, slowly dropping to 850 as the coolant warms up. on a very cold winter moring it will go even higher for the first couple of mins.
the fluctuation to 1600 rpm should not occur, but it is expected when you have a dirty throttle body, the idle speed control actuator has to react because the ecu's expected rpm to actuator position map is made inaccurate by the dirt so it then has to compensate by adjusting the actuator position (causing the rpm fluctuation). why it doesnt learn this change permanently is anyone's guess, most cars do make permanent adaptations, but it seems you need to use an examiner to force it to relearn on these cars.
any less than 1250rpm this time of year is a sign your coolant temp sensor is faulty or the idle speed control actuator is faulty or your throttle body is desperate for a clean.