LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 950 (Engine Controls - Powertrain DTC Charts And Descriptions - (Hybrid)) >> DTC Diagnosis >> P0135 - O2 Heater Circuit (Bank 1, Sensor 1)

P0135 - O2 Heater Circuit (Bank 1, Sensor 1)

WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
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: 
  • 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:  Inspect the sensor, wiring, and connectors for damage, corrosion, or water intrusion.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All   refer to PINPOINT TEST DW .