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

Circuit is monitored after engine has been idling for at least 12 seconds, with battery voltage more than 9 volts, engine coolant temperature less than 147°F (64°C) and ambient temperature within 27°F of engine coolant temperature. DTC will set when 1/1 HO2S voltage is more than 3 volts for 30-90 seconds. Possible causes are: defective 1/1 HO2S, heater control circuit open or shorted to ground, ASD relay output circuit open or defective PCM.