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Steve
Steve, Ford Technician
Category: Ford
Satisfied Customers: 6913
Experience:  30 years working for Ford dealer. Ford Master tech.
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1998 Escort: 2.0L p0135..02 Sensors and still get the same code

Resolved Question:

1998 Escort 2.0L P0135. Changed both 02 Sensors and still get the same code. Replaced the upper sensor a 2nd time and same code. Now thinking to replace the Canister Vent Solenoid, but not sure what to do.
Submitted: 5 years ago.
Category: Ford
Expert:  Steve replied 5 years ago.

Steve :

Hello and Welcome to Justanswer, My name is XXXXX XXXXX I am here to try and assist your with your question

Steve :








P0135 - HO2S Sensor Circuit Malfunction (HO2S-11)During testing the HO2S Heaters are checked for opens/shorts and excessive current draw. The test fails when current draw exceeds a calibrated limit and/or an open or short is detected.

  • Short to VPWR in harness or HO2S.

  • Water in harness connector.

  • Open VPWR circuit.

  • Open GND circuit.

  • Low battery voltage.

  • Corrosion or poor mating terminals and wiring

  • Damaged HO2S heater.

  • Damaged PCM.




  • Wiring.

  • Damaged HO2S heater.

  • Damaged PCM.


Steve :

the o2 senor is the front one on the exhaust manifold

Steve :

check it for power with the key on on the white wire going to the 02 sensor

Steve :

You are missing the power to the 02 sensor to heat it up

Customer:

I have not had the chance to check the power on the white wire for the 02 Sensor. Wanted to ask a followup question about if there is no power for the heater on the 02 Sensor, should I just replace the PCM with a used one from a junk yard? I think there is a pin on the PCM to check for power also but wondering how much I can do with just a Sears omh meter.

Steve :

hi

Steve :

the power comes from the fuel injector fuse. If the engine is running the fuse is good

Steve :

if there is no power to it then you have a open wire and you need to trace it find the break in the wire harness

Steve :

check at the connector pull on the wire and see if it breaks or is broken

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