P0138

Tests 205 - 209:

Tests 210 - 215:

Test 216:

SYMPTOM
P0138 - 1/2 O2 SENSOR SHORTED TO VOLTAGE

WHEN MONITORED
With engine running for more than 2 minutes and engine coolant temperature above 170 °F.

SET CONDITION
The oxygen sensor voltage is above 1.2 volts.

POSSIBLE CAUSES
- O2S sensor ground circuit open
- Open ASD relay output circuit
- O2S signal circuit open
- O2S heater ground circuit open
- O2S signal circuit shorted to voltage
- Wiring harness intermittent defect
- O2S defective
- PCM defective