Checking Oxygen Sensor Heater

Tests 1 - 3:

Tests 4 - 8:

SYMPTOM
CHECKING OXYGEN SENSOR HEATER

POSSIBLE CAUSES
- 1/2 O2 sensor voltage between 0.4 V & 0.6 V
- 1/1 O2 sensor defective
- 1/2 O2 sensor defective
- ASD relay output circuit open (1/1 O2 sensor)
- ASD relay output circuit open (1/2 O2 sensor)
- Heater ground circuit open (1/1 O2 sensor)
- Heater ground circuit open (1/2 O2 sensor)