My 2013 Highlander threw a P0128 code, was running cold and trac control wouldn’t turn on. Heater was working at this point.
I changed the thermostat out. (Had to remove serpentine belt to reach housing.) Put everything back together and ran air out of coolant line. Now the car heats to normal temp but the heater doesn’t work. Still has a P0128, but also threw a P0300 (random cylinder misfire). Also the power windows are not working.
Is there an obvious place I should be looking?
Second this, air in the cooling system on newer vehicles can lead to a poor idle the system actively uses the coolant temperature to determine how it should run if air is passing by the sensor it will momentarily read at a different temp.