D15: Check For O2 Sensor Continuity

With EM012 and EM022 disconnected, measure the resistance between EM012/017 and EM022/002.

Is the resistance < 0.5 ohms?

Yes
GO to D16, D16: O2 Sensor Screen Ground Continuity

No
Inspect harness/connectors EM012 and EM022 for corrosion, damaged/pushed back pins.
Repair as required and reconnect plug(s).
GO to D21, D21: End