P0157

Tests 1 - 4:

Tests 5 - 8:

Test 9:

SYMPTOM
P0157-O2 SENSOR 2/2 VOLTAGE LOW

TEST NOTE
This symptom is diagnosed using the test 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
- Intermittent condition
- O2 sensor
- O2 sensor return circuit shorted to ground
- O2 sensor signal circuit shorted to ground
- O2 sensor signal circuit shorted to sensor return circuit
- O2 sensor signal shorted to heater ground circuit
- PCM return circuit
- PCM signal circuit