Quote:

iagnostic Trouble Codes (DTCs) P0135 P0141, P0155 and P0161 indicate a short to ground, open, or short to VPWR in the HO2S heater circuit.

DTC/HO2S Reference List:

DTC P0135 = HO2S HTR-11

DTC P0141 = HO2S HTR-12

DTC P0155 = HO2S HTR-21

DTC P0161 = HO2S HTR-22

Possible causes:

-- Shorts to VPWR in harness or HO2S.

-- Water in connectors.

-- Cut or pulled wires.

-- Disconnected wiring.

-- Open VPWR circuit.

-- Open GND circuit.

-- Low battery voltage.

-- Corrosion or poor mating terminals.

-- Damaged HO2S heater.

-- Damaged PCM.

l NOTE:
On some applications, a vehicle hoist is required to access the HO2S harness.

Visually inspect the HO2S circuit for exposed wiring, contamination, corrosion and proper assembly.

l Were any concerns found during the visual inspection?

Yes
REPAIR any concerns found in the visual inspection. COMPLETE PCM Reset to clear DTCs. RESTORE vehicle. RERUN �«Quick Test�».

No
GO to �«H31�».



Downstream sensor front bank. Inspect the connector for corrosion/damage, etc. Test heater element with an ohmmeter for failure.

Steve

98 Contour SE Sport 2.5 Duratec ATX The wifey's car 89 Taurus SHO - 246K miles 94 SHO ATX - 190K 1997 F-150 5.4L ATX - The Workhorse 150K. ANY THREAD WITH "OMG" or "WTF" ETC IN THE TITLE WILL BE IGNORED!