1999 Civic EX O2 sensor wire help needed - removing O2 simulator
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1999 Civic EX O2 sensor wire help needed - removing O2 simulator
Hi,
I am new here. I purchased a '99 2 door civic ex with the CEL on. After codes were diagnosed, I replaced both o2 sensors. While replacing the secondary sensor, I found that the previous owner had installed an o2 simulator and had spliced into the factory wiring between the harness and the ECU. I removed the o2 simulator and rewired the original wires back together. However, I am having an issue with the primary white/red wire. It has a second uncoated wire that is inside the outer insulation but is separated from the primary wire by the primary's insulation. I have searched online everywhere and cannot find out what this is. I even stopped at the Honda dealership and they looked at their books and could not tell. They thought maybe it was another ground or insulation. But the green wire is the ground and it is not wrapped around the wire like insulation. It is off to the side like another wire. I am including a picture for reference. The wire I am trying to find out about is the silver one that is inside the larger grey wiring that also includes the primary red/white wire. Any thoughts? Thanks!
I am new here. I purchased a '99 2 door civic ex with the CEL on. After codes were diagnosed, I replaced both o2 sensors. While replacing the secondary sensor, I found that the previous owner had installed an o2 simulator and had spliced into the factory wiring between the harness and the ECU. I removed the o2 simulator and rewired the original wires back together. However, I am having an issue with the primary white/red wire. It has a second uncoated wire that is inside the outer insulation but is separated from the primary wire by the primary's insulation. I have searched online everywhere and cannot find out what this is. I even stopped at the Honda dealership and they looked at their books and could not tell. They thought maybe it was another ground or insulation. But the green wire is the ground and it is not wrapped around the wire like insulation. It is off to the side like another wire. I am including a picture for reference. The wire I am trying to find out about is the silver one that is inside the larger grey wiring that also includes the primary red/white wire. Any thoughts? Thanks!
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Re: 1999 Civic EX O2 sensor wire help needed - removing O2 simulator
I was trying to figure out where that pic is. The center console!
White/red IS a shielded wire (coax), looks like it only runs between that connector and the ECM. The shield (outer wrap) is grounded at one end, to protect the signal wire from external electrical interference.
It's like coax wire for cable TV, the center wire carries the signal while the outer layer shields it from interference.
Is that what you needed to know?
White/red IS a shielded wire (coax), looks like it only runs between that connector and the ECM. The shield (outer wrap) is grounded at one end, to protect the signal wire from external electrical interference.
It's like coax wire for cable TV, the center wire carries the signal while the outer layer shields it from interference.
Is that what you needed to know?
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Yes, I was just coming back on to say that I think it is a shielded wire and I saw your reply. Thanks for the help. My next question would be whether it should be grounded on this end or not. I read a little about shielded wiring and saw that it should only be grounded on one end in order to avoid ground loop. I'm not sure if the side connected to the ECU is grounded or if I should ground the end showing?
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Yes, I was just coming back on to say that I think it is a shielded wire and I saw your reply. Thanks for the help. My next question would be whether it should be grounded on this end or not. I read a little about shielded wiring and saw that it should only be grounded on one end in order to avoid ground loop. I'm not sure if the side connected to the ECU is grounded or if I should ground the end showing?
If you check it with a meter, you should find it is already grounded.
I believe it is grounded only at the end nearest the computer.
I even stopped at the Honda dealership and they looked at their books and could not tell.
The knock sensor, when equipped, is another that uses shielding on the signal wire. IIRC the shields all share the same grounding circuit(s) near the PCM.
HTH
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