A10: Signal Ground 2 Continuity

With EM010 & EM014 disconnected, measure the resistance between EM014/004 & chassis ground EM008L

Is the resistance < 0.5 Ohms?

Yes
Go to A12 A12: Check For Heated O2 Sensor Continuity

No
Inspect connector EM014 for corrosion, damage, or pushed back pin Inspect ground stud EM008L for corrosion
Repair as required, harness, splice EMS36, connector or ground; reconnect plug(s)
Go to A11 A11: Stop