P0143 1/3 O2 Sensor Shorted to Ground

SYMPTOM
P-0143 1/3 O2 SEN SHORTED TO GROUND

WHEN MONITORED
With engine coolant temperature above 170 degrees F on the previous key on, after a cold start, engine coolant below 98 degrees F, and ambient battery sensor reading within 27 degrees F of engine coolant.

SET CONDITION
The oxygen sensor signal voltage is below 0.156 volts for 28 seconds after starting engine.

POSSIBLE CAUSES
- O2 sensor 1/3 defective
- O2 sensor 1/3 terminal observable defect
- O2 sensor 1/3 wiring harness inter short to gnd
- PCM defective (1/3 O2 sensor short to ground)
- PCM terminal observe defective
- O2 SEN 1/3 signal ckt intermittent short to ground
- O2 sensor 1/3 signal circuit short to ground