P0138

Test 1 - 4:

Test 5 - 6:

SYMPTOM
P0138 - O2 SENSOR 1/2 VOLTAGE HIGH

Test Note
This symptom is diagnosed using the test P0132-O2 SENSOR 1/1 VOLTAGE HIGH.

WHEN MONITORED
The engine running for 119 seconds. O2 Sensor Heater Temperature is greater than 350 °C (662 °F). Battery voltage greater than 10.99 volts.

SET CONDITION
The Oxygen Sensor voltage is above 3.9902 volts for 30 seconds. Two trip fault.

POSSIBLE CAUSES
- 02 Sensor voltage above 3.7 volts
- 02 Sensor signal circuit shorted to voltage
- 02 Sensor return circuit shorted to voltage
- 02 Sensor
- 02 Sensor signal circuit open
- 02 Sensor return circuit open
- PCM