P0131

Tests 1 - 2:

Tests 3 - 5:

SYMPTOM
P0131 - 1/1 O2 SENSOR VOLTAGE SHORTED TO GROUND

WHEN MONITORED
With the ignition key off, after the 02 Sensor cools down; and after the next key on provided that it is a cold start (coolant temperature less than 38 °C (100.4 °F)) and ambient temperature within 13 °C (7.2 °F) of coolant temperature.

SET CONDITION
The upstream 02 Sensor Signal voltage is below 0.156 volt prior to O2 Sensor Heater test (cool down period), and O2 voltage less than 0.156 volt after the key on in the subsequent start.

POSSIBLE CAUSES
- 1/1 O2 sensor voltage low
- 1/1 O2 sensor signal circuit shorted to ground
- 1/1 O2 sensor signal circuit shorted to ground circuit
- 1/1 O2 sensor defective
- PCM defective (1/1 O2 sensor)