G2: Check For O2 Sensor Failure

Run the engine for a period to warm the sensor and then maintain a steady speed of approximately 2500 rpm.
Measure the voltage between EM024/001 and EM024/002.

Is the voltage between 600mV and 1.0 Volt?

Yes
GO to G3, G3: Check For O2 Sensor Failure

No
Renew O2 sensor and reconnect plug(s)
GO to G6, G6: Stop