Dealer has had 2.7L Bronco for 2 weeks for P2240 Check Engine Code

[Dtseligman]

Morning,

Looking for some advice or other things to consider. The dealership has had by 2.7L 4dr Heritage Sasquatch for 2 full weeks trying to diagnose O2 Sensors problem. I took the truck in when an engine code came up. They had the truck for a week and said their first steps were to unplug/plug back in and perform resistivity testing. They said they light went away. I remote started the Bronco for the first time and the light was on. Left the vehicle for further work. They got back to me days later saying they are having trouble locating some wire harness for the system. They couldn't locate the harness and need to dig deeper into the truck.
Here is the thing I'm concerned about: they mentioned they might need to "open a case with Ford" if they cannot get it fixed. I will know by end of day today if it is complete or not.
Any thoughts from folks? I never asked for a rental but will if they hold onto the vehicle passed this evening. What does opening a case with ford entail? What is Lemon Law and could that be useful? Any other input? Truck has 9k miles so I'm not happy its been in the shop for 2 full weeks on an O2 sensor.

Thanks!

UPDATE:
Got the Bronco back a couple days ago with replaced O2 sensors. 2 weeks plus 2 days.

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[PWillette]

@flip may be able to assist.

 

[FourHorses]

I can's speak to your exact issue, but in my experiences this has become the new norm. Waiting on the dealer for weeks for warranty diagnosis and repair. My dealer has had my expedition for almost three weeks, and before that they had my explorer for 5-6 out of 8 weeks. Still no fix on either. Mine typically diagnosis fairly quick, but the repair takes forever whether its parts or labor or what I don't know. They had my expedition three different times last year within a few months. Phasers, water pump and then a leaking overflow canister and heater hose that I believe they caused when they did the phasers. Beyond frustrating.

 

[flip]

The code is saying there is a signal issue on either the BN-BU or WH wires on the driver front sensor. The pin point test has them check wire resistance from the connector at the O2 to the PC, if it's below 5 ohm and there are no pins messed up, pushed out, corroded and only the code, it says to replace the sensor and reset the keep alive memory.

The figure 8 looking thing on those wires indicates they're shielded to prevent RF or other interference. Should be pretty straight forward if the wires and terminals are good, a new sensor doesn't fix it, then it's probably a the PCM. That said, you can have acceptable resistance in a wire but it not be able to carry current if the copper strands are interrupted or damaged. I don't believe there's much current on these since it's signal.

Some of this shit is getting really complicated and might require an oscilloscope either the Ford one or Picoscope to check for "noise". We've seen weird shit happen when coils go bad and produce a lot of RF. Could also have a little corrosion bridging between the wires which can be nearly impossible to detect just with impedance testing. If there's a question of wiring, we would overlay the wires to bypass anything in between the sensor and PCM as a process of elimination if normal diag doesn't lead to a resolution.

 

[SwissBronco]

Iirc there was a recall on the harness touching the driveshaft. Might be worth a look under.

Then have the battery load tested. These days batteries are creating lots of gremlins. A simple volt measure is not enough.

 

[Ford Motor Company]

Morning,

Looking for some advice or other things to consider. The dealership has had by 2.7L 4dr Heritage Sasquatch for 2 full weeks trying to diagnose O2 Sensors problem. I took the truck in when an engine code came up. They had the truck for a week and said their first steps were to unplug/plug back in and perform resistivity testing. They said they light went away. I remote started the Bronco for the first time and the light was on. Left the vehicle for further work. They got back to me days later saying they are having trouble locating some wire harness for the system. They couldn't locate the harness and need to dig deeper into the truck.
Here is the thing I'm concerned about: they mentioned they might need to "open a case with Ford" if they cannot get it fixed. I will know by end of day today if it is complete or not.
Any thoughts from folks? I never asked for a rental but will if they hold onto the vehicle passed this evening. What does opening a case with ford entail? What is Lemon Law and could that be useful? Any other input? Truck has 9k miles so I'm not happy its been in the shop for 2 full weeks on an O2 sensor.

Thanks!

Hey there. Can you send over a message with your VIN and the name/location of the Ford dealer you are currently working with? I would like to see what I can do to assist with your Bronco's repairs

 

[Patrickgault]

I've had @Ford assist with some of my 2022 issues, however their involvement didn't amount to much help at the dealership. I'm thinking that it's good for traceability reasons. Good luck with the repairs.

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