DTC P0135: O2 Heater Circuit (Bank 1, Sensor 1)

P0135 - O2 HEATER CIRCUIT (BANK 1, SENSOR 1)

Description:	During testing the heated oxygen sensor (HO2S) heaters are checked for open and short circuits and excessive current draw. The test fails when the current draw exceeds a calibrated limit or an open or short circuit is detected.
Possible Causes:	Vacuum hose disconnected on exhaust gas recirculation (EGR) system module (ESM) applications Short to VPWR in the harness or HO2S Water in the harness connector Open VPWR circuit Open GND circuit Low battery voltage Corrosion or incorrect harness connections Damaged HO2S heater
Diagnostic Aids:	Check the HO2S electrical connector for damage, corrosion, and water intrusion. Damaged HO2S heater.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to Pinpoint Test DW .