P0131

Test 1 - 4:

Test 5 - 8:

SYMPTOM
P0131-O2 SENSOR 1/1 VOLTAGE LOW

WHEN MONITORED
Engine Running for less than 30 seconds. O2 Sensor Heater Temperature less than 251° C (484° F) Battery voltage greater than 10.99 volts.

SET CONDITION
The oxygen sensor signal voltage is below 2.5196 volts for 3 seconds. One trip Fault.

POSSIBLE CAUSES
- O2 sensor below 2.52 Volts
- O2 sensor
- O2 return circuit shorted to ground
- O2 signal circuit shorted to ground
- O2 signal circuit shorted to O2 return circuit
- O2 signal shorted to heater ground circuit
- PCM return circuit
- PCM signal circuit