B16: Check For Short to B+

Measure the voltage between EM010/023 and EM012/022

Is the voltage 0 (zero) V?

Yes
GO to B17, B17: Check For Short To B+ At O2 Sensor Heater

No
Inspect harness/connectors EM010, EM012 and EM021 for corrosion, damaged/pushed back pins. Repair as necessary and reconnect plug(s).
GO to B19, B19: End