B3: Check For O2 Sensor Heater Continuity

Ignition switch to position 0
Disconnect EM021

Bracket on top of gearbox or Bulkhead rear of engine

With EM021 disconnected, measure the resistance between EM021/001 and EM021/002.

- Is the resistance between 4 and 10 ohms?
Yes
GO to B4 B4: Check For O2 Sensor Failure
No
Renew O2 sensor, reconnect plug(s).
GO to B8 B8: Stop