Ecobee ecobee4 - Ventilator (2-Wire Set Up): Step 2 Diagram

VENTILATOR (2-WIRE SETUP)
ACC+
ACC-
W2
W1
C
R
H
ERV/HRV
R G (HI/LO)
NOTE During setup, select 2-wire (ACC+, ACC-) accesory on the
thermostat screen.
Step 2: Wire the ventilator as shown below.