H14 - Check HO2S Integrity
Heated Oxygen Sensor (HO2S) always lean, slow to switch or lack of switching. Fuel at adaptive limit could be caused by:
- Moisture inside the HO2S harness connector resulting in a short to ground.
- HO2S coated with contaminants.
- HO2S circuit open.
- HO2S circuit shorted to ground.
- Key "OFF".
- Inspect the HO2S harness for chafing, burns or other indications of damage. Service as necessary.
- Inspect HO2S and connector for indication of submerging in water, oil, coolant, etc. Service as necessary.
- Run engine at 2000 rpm for two minutes.
- Key "OFF".
- Run Engine Running Self-Test. Key ON Engine Running (KOER) Self-Test
- Are fault codes present?
Yes -- Go to H16. H16 - Check HO2S On Engines With MAF Sensor
No -- Go to H21. H21 - Check Resistance of Heated Element On HO2S