EGR Learned Minimum Position

The scan tool displays 0-5 volts. This represents the learned voltage that the PCM uses to determine whether or not the EGR valve is fully closed, and at 0 percent pintle position. If the desired EGR position is 0 percent, and a difference of more than 0.4 volt between EGR feedback and EGR closed valve pintle position is detected, DTC P1406 will set.