SOLVED: Electrical Issues - Lost Communications and Invalid Data Received

[wifeys-ST]

Occasionally our 2020 is having somewhat random electrical issues. (Our battery is OEM so I’m considering just replacing it but it keeps testing in good health. EDIT: I replaced the battery and reset the BCM and all codes and am still getting these issues 3 days later.)

the most serious issue we have is that after startup, when we go to reverse out of our spot, the car will just roll with foot on the brake. It does this until you release and press a few times. Once i stopped it by pressing EXTREMELY hard. Basically stood on the pedal. But if i put the car in park and turn it off and restart, the issue is completely solved. It never does this when cruising, just the first tine we drive off. Zero codes or DTCs.

One time our whole center console navigation screen rebooted on the freeway. This DID cause a DTC.
Today i started the car and started to reverse and instantly the whole dash lit up. I attached the codes from this event.

after clearing the codes and restarting the car everything was fine but one IPMA dtc about brake module A came up in forscan after the restart.

Hoping someone will tell me to replace the battery and all my problems will be solved. Please anyone with experience with this give your input.

these all seem like communication issues. Either some bug in the software or battery intermittent issues or a faulty connection i can clean and check.

Thank you

 

[wifeys-ST]

Update: I put a fresh battery in it and reset the BCM. Went a whopping 3 days without issues until I got these again. I will scan later with forscan, i’m expecting it to be the same error codes as before.

 

[wifeys-ST]

These are the new codes. I’m going to check my FADA connector since I performed the TSB to upgrade the FADA to a solid intermediate shaft. I’m wondering if the old dangling connector is starting to short out or get corroded. Will probably cut and terminate it properly and see if symptoms appear again.

 

[wifeys-ST]

Wow this was useful: https://www.foexplorer.com/ford_explorer_diagnosis_and_testing_dtc_chart_and_pinpoint_tests-822.html. things are pointing towards awd module grounding issues. Also found some other threads that shared the same codes as me but it ended up being a bad Tcase. I'm hoping that its just the ground issue.

 

[Cdubya]

Wow this was useful: https://www.foexplorer.com/ford_explorer_diagnosis_and_testing_dtc_chart_and_pinpoint_tests-822.html. things are pointing towards awd module grounding issues. Also found some other threads that shared the same codes as me but it ended up being a bad Tcase. I'm hoping that its just the ground issue.

The AWD module grounding issues seems to have a different set of codes than you though? Did you look at the AWD grounding module TSB? Also, what is the deal with the brake code? Very strange. Loss of communication with various modules sporadically are no big deal. I see those logged all the time. But those that repeatedly come up even when cleared are real issues IMHO. BTW, when you did the FADA delete, you did reprogram the AWD module firmware with FDRS?

 

[Stone17]

This.

 

[wifeys-ST]

The AWD module grounding issues seems to have a different set of codes than you though? Did you look at the AWD grounding module TSB? Also, what is the deal with the brake code? Very strange. Loss of communication with various modules sporadically are no big deal. I see those logged all the time. But those that repeatedly come up even when cleared are real issues IMHO. BTW, when you did the FADA delete, you did reprogram the AWD module firmware with FDRS?

Thanks for the feedback. Yea i agree. I haven’t found a smoking gun that matches the same codes as me that keep coming up. They seem related but not identical.
Yes, when I did the FADA upgrade i used FDRS to update the AWD module and told it that the connector was not present, it drove fine after that for a long time no errors of any kind.
I read through the TSB and the troubleshooting steps for the AWD grounding. I plan to add a dedicated ground to it regardless since it certainly would not hurt or cost me much time/money and I feel comfortable doing it myself.

at the very least it would rule that issue out. I need to spend some time trying to read more sensor data with forscan. The issue was intermittent but now seems to be a full time problem since the last time i cleared the codes they came back immediately.

 

[wifeys-ST]

This.

Thanks for sharing. man i can’t imagine a dealership taking all of those panels and seat off just to do that tiny job. I have two babies and a week long trip coming up but when I get back I’m going to test this.

 

[wifeys-ST]

Found something very interesting. My AWD module voltage is very low compared to the rest of my module voltages.

 

[wifeys-ST]

Notice AWD module Voltage Low DTC after the engine was already running for some time. I’m hoping this is just an AWD module ground issue. Going to attempt to check the ground right now. Gotta figure out how to pull the carpet up

 

[wifeys-ST]

You guys wont believe this but wiggling the connector under my seat to the awd module fixed everything and i caught it live in a forscan recording. All the disabled features are back online and forscan is not showing any more codes. I might just drive it to ford and show them what i found and see what it would cost for them to do the grounding TSB.

 

[wifeys-ST]

SOLVED: AWD module under the seat had a poor ground with ~50Ohm resistance to the body and i was reading 2.3 volts on the ground of the FADA connector. I wiggled the connector going to the module under the seat and the grounds completely cleaned up to 0ohms and no more voltage on the ground pin of the FADA connector.

I'm going to perform this TSB myself for a more permanent repair.

BTW this TSB does not exist anywhere anymore. It has been removed from Ford's database. I called ford and asked them about it, they say they have no record of it. I emailed the TSB to them and the guys was pretty surprised he said they can't find it anywhere. My best guess is that they have an updated AWD module that no longer has the ground short issue and they expect you to just replace the AWD module with the new module. But for 300$ module plus 2 hrs of labor plus programming. That's an expensive job when some 16 awg wire, crimp, and a ring terminal can to the job for pennies at home.