Rerouted Oxygen Sensor Wires, PCM is Throwing a P0132 Code

Discussion in 'The Projects Forum' started by fcastro, Jun 24, 2009.

  1. fcastro

    Thread Starter New Member

    Jun 24, 2009
    4
    0
    Hi everyone, first time poster here. I am more of an engine guy then an electrical guy so was wondering if I could get a bit of advice from the pros :D

    This isn't an easy post but I am going to try to condense it as much as possible. Recently my 2000 4.7 durango power steering pressure switch failed and it started to pump power steering fluid into my harness (common issue). The fluid got as far as my upstream oxygen sensor and fouled it up.

    Rather then reusing the wires at the connector (x4), I decided to just rerun 3 of 4 new wires to the PCM seeing as it seemed like an easy task (Simple circuit). I got the wiring schematics, and then ran a new wire to the sensor signal, pcm ground, and common ground (its the ground for the heater wire) up near the pcm main harness (using the same 18 gauge wires) from the new o2 sensor. The last wire which is the 15 amp fused heater wire I just reconnected seeing that it was not fouled.

    I connected the o2 sensor signal wire by cutting it and butt spliced with the pcm's wire. For the 2 grounds I just used a crimp connectors.

    I then picked up a bosch universal sensor and plugged it in. After running the car for a few minutes, the pcm is threw a p0132 "1/1 O2 Sensor Shorted To Voltage": description: Oxygen sensor input voltage maintained above normal operating range.

    Considering I ran all new wires I was wondering if anyone had any insight as to what the problem could be? One Dodge tech suggested getting the OEM sensor which is by Denso, but I have already cut into the harness so it doesn't make much sense imo unless the sensor from bosch is not as high quality.

    Thanks for taking the time to read this, any insight would greatly be appreciated :)
     
  2. Externet

    AAC Fanatic!

    Nov 29, 2005
    758
    57
    Perhaps you confused/swapped sensor out and heater+ wires when splicing.

    Measure the voltage at the compfuser input pin for the sensor; should be ~0.45 V.

    Miguel
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Narrowband Lambda sensors (O2 sensors) toggle between around 0.1v-0.2v and 0.8v-0.9v depending upon the absence or presence of oxygen. If you've managed to contaminate your O2 sensor, it won't toggle; it'll stay near 0.8v-0.9v, telling the ECU that the fuel/air mixture is too rich, and the ECU will lean out the mixture. The midpoint is around 0.4v-0.45v, but it won't sit there; it rapidly switches from "too rich" to "too lean" due to the ECU continually adjusting the mixture.

    Here's a troubleshooting guide:
    http://www.autodiagnos.com/fileadmi...bulletins/misc/gea_testing_lambda_sensors.pdf
     
  4. fcastro

    Thread Starter New Member

    Jun 24, 2009
    4
    0
    Hi guys thanks for the input.

    As far as the wires go they have been double checked. I also actually labeled them with stickers and did continuity tests afterwards.

    The sensors on this truck produce voltage between 0-1v. Normal range is usually .4-.6v as sgt mentioned.

    Quick question could using crimp connectors for the grounds somehow change the ground? I guess since I am not huge on electricity is there a way with a multimeter to tell if a ground is better then another one? I would assume that resistance changes no?
     
  5. Externet

    AAC Fanatic!

    Nov 29, 2005
    758
    57
    About the grounds, highly unlikely.

    First; were the trouble code erased before transplanting the sensor? It could belong to the older one.

    Disconnect the Ox sensor completely, erase trouble codes and run the car to check if same or other code shows up. If the sensor shorted to +12V code dissappears; you do have a bad sensor or misidentified wires.

    Measure the sensor continuity out of circuit looking for +12 bridged to Ox sensing pin.

    Miguel
     
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