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Discussion Starter · #1 ·
I apologize for all the posts but I think I’m on to something and potentially found the problem that’s causing all kinds of issues. I have an issue with my B1S2 (downstream) O2 sensor. Codes we’re p1621/1622. After researching a bit, determined that the O2 sensor codes relate to the heater circuit. Changed all 4 O2s with what I think are OEM from eBay. No change. I then learned that Chryslers heat their O2 sensors not from the PCM but from the ASD relay
Was about to change out the B1S2 with a rock auto ordered O2 until I discovered this today behind the TIPM:

Tire Wheel Automotive tire Hood Tread

yup, looks like remnants of a rodents nest!

analyzing further, I found this:

Wood Electrical wiring Electrical supply Wire Recreation

That appears to be a wire that is partially chewed and lacks a good connection. Possibly the heating wire from B1S2 O2 sensor that’s been causing me so much grief.

anyone would be so kind as to share the wiring diagram for the O2 sensor heater wires going to the ASD relay? I would be very grateful!!
 

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Discussion Starter · #2 ·
A Good Samaritan on FB provided me with the diagram. According to the codes, there could be an issue with the return circuit. Apparently B1S2 return circuit is S904 wire loom. Anyone happen to have this? My money is that chewed up line is in the s904 wire loom. It makes sense because when B1S2 is plugged in, it drags b2s2 down, which just so happens to be spliced with each return lines.
Rectangle Slope Font Parallel Schematic
 

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Discussion Starter · #3 ·
I’m posting this in hopes that my plight that would have likely left most people to dump their cars, with some semblance on what to do. So far, the main lesson I’m learning is to look for clues. About a month ago I saw this hair in the engine bay, didn’t give it much thought until I read up on all these issues with rodents. I could be totally wrong at this point and that wire’s integrity could be unrelated, but really have not much to lose but to try to get it fixed. Thanks to all that have helped on this very difficult issue. Very appreciative. These electrical problems is not for the faint of heart.
 

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Cut it, splice it, using crimped connectors and coat with liquid electrical tape. Wrap with Magic Wrap or black Cloth tape. Split wire loom it, may as well.

Liquid electrical tape comes in red, black maybe other colors.

Magic Wrap Plumbers Tape stretches and bonds to itself like rubber. Won't peel.
 

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Discussion Starter · #7 ·
Thanks Jeepman. I’m not well versed in soldering and all that electrical stuff so I brought it down to a garage just a block away from my place. I told the mechanic the issue and he said he’s seen this
with three Dodge’s already, all in the same place!!! He knows what to do. Said it’ll be done by the end of the day.

I was told that the dealer, had I brought it in, would have recommended a whole new wiring harness. I can’t imagine escaping the dealer with no more than $2000 worth of work.

My OEM sensor from rock auto is arriving today. If everything works, I’m going to return the sensor and take a loss with the shipping.

the area where the wires are chewed, it appears Chrysler cheaped out on the insulation and only have one layer of electrical tape on that wire loom. There is a nice space in the area where rodents can live. I’d recommend reinforcing the wiring on that wire loom with some hard plastic loom, which is something I plan to do once this nightmare is over.
 

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Better be careful, that may be a protected area for the Piping Plover or Piping Mouse. Maybe you have a better name for the culprit. :)
 
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Discussion Starter · #9 ·
Better be careful, that may be a protected area for the Piping Plover or Piping Mouse. Maybe you have a better name for the culprit. :)
Well, bad news, they opened up the wire loom, no damage to any wiring. So i guess I owe that rodent an apology! Shop said it’s likely the O2 sensor. Luckily the Rockauto sensor comes in today. Will slap that on and go from there.
 

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The least you could do is put the nest back together. :)
Good luck with the sensor.
 

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Discussion Starter · #11 ·
The least you could do is put the nest back together. :)
Good luck with the sensor.
Thanks Jeepman. I asked whether a relearn is necessary and the mechanic said he has never needed a relearn for an O2 sensor. He’s also never seen an O2 sensor codes like I have go away when I unplug the sensor. So hoping it’s the actual sensor!
 

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No relearn required for an O2 sensor for sure. A relearn just clears learned computer settings back to factory settings like for some major transmission work. The computer can redo the process of learning (relearn). Sometimes done with a transmission fluid change, the transmission readjusts to the new fluid.
Also have heard the term used with throttle body drive by wire systems. A recalibration.
 

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Discussion Starter · #13 ·
Installed new O2 sensor B1S2 from rock auto. Did not work. The car at first sounded like it worked but a few seconds later hear the familiar hesistation (very light and not very noticeable). Checked the codes and sure enough they returned. I think I’ve done all I could. I hear a slight air vacuum sound, checked the engine bay but couldn’t find it. Can’t imagine a vacuum leak would be throwing these codes. A mechanic mentioned a possible faulty MAP sensor. Could a PCV valve throw this code? I don’t know.

is there a period of time for the O2 sensor to work with the PCM? I even had a neighboring shop reset the PCM and codes still stayed. I noticed this one appears to run with less voltage than the other O2 sensor I just removed. Wonder the whole “drive the car for four heat cycles then the codes will reset” will work. I’m thinking not but holding out for hope.

I’m most likely going to schedule a visit with the dealer and pay the diagnostic fee to let them figure this out. Alternatively I can just run with B1S2 unplugged. Can’t imagine that’s good for the car long term but that seems like a real alternative if I can’t figure it out.
 

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