P0140 1/2 O2 Sensor StaysAt Center

SYMPTOM
P-0140 1/2 O2 SENSOR STAYS AT CENTER

WHEN MONITORED
With engine running for more than two minutes, engine temp greater than 170 degrees F, in closed loop.

SET CONDITION
If oxygen sensor volt stays between 0.29 and 0.72 for 30 seconds, the PCM pulls the sensor volt to 5.0 volts for 60 seconds and monitors the sensor voltage. If voltage stays at 5 volts, this TC will set indicating no activities.

POSSIBLE CAUSES
- 1/2 O2 sensor connector observable defect
- 1/2 O2 sensor signal circuit open
- 1/2 Oxygen sensor ground circuit open
- PCM Connector observable defect
- 1/2 Oxygen sensor defective (in range)
- 1/2 Oxygen sensor defective (out of range)
- PCM defective