DTC P0135: 1/1 O2 Sensor Heater Failure: Description

1/1 Heated Oxygen Sensor (HO2S) heater voltage is monitored with engine at idle immediately after a cold start, with engine coolant temperature less than 147°F (64°C) and ambient/battery temperature is within plus or minus 27°F (-3°C) of engine coolant temperature. DTC will set in Powertrain Control Module (PCM) memory when PCM senses 1/1 HO2S voltage is more than 3 volts for 30-90 seconds. Possible causes for DTC to set are: defective 1/1 HO2S, defective PCM, or defective connectors or wiring.