F12: Signal Ground 2 Continuity

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

Is the resistance < 0.5 ohms?

Yes
GO to F14, F14: Heated O2 Sensor Screen Ground Continuity

No
Inspect harness/connector EM014 for corrosion, damage, or pushed back pin.
Inspect earthing stud EM008L for corrosion or damage.
Inspect harness/splice EMS38 for damage.
Repair as required and reconnect plug(s).
GO to F13, F13: Check For Heated O2 Sensor Continuity