Communication issues?

REGGINA

MEMBER
2012 FORD F-150
3.5L
V6
TURBO
4WD
AUTOMATIC
170,000 MILES

I bought this truck with 90k, and around 110k it started having the most bizzare electrical issues. Dash goes nuts, shuts off/on, stays off, service advanced trac and other warning lights come up, shifts into 4WD randomly. It only really happens when its below 40 degrees. The colder it is, the worse it is. I have to drive in 4WD in the winter time for about a half hour until the truck warms up, then it will stop. If its below 0, my headlights will turn on and off as they please with the lights set to Off and keys out.

I am at 175k now, so it is what it is at this point, just curious what you guys might think. I had it at the ford dealership 5 years ago when I bought it and they were stumped, replaced a bunch of modules, went through wiring/rewrapped it. Here's a video and some codes that it throws:

https://youtu.be/HVFj174m6Is?si=8-vBmJ96e4nc1z73

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Friday, July 4th, 2025 AT 9:41 AM

6 Replies

REGGINA

MEMBER
5 POSTS

It must've through all the codes in my first post because of my battery getting weak/low voltage, these are the normal amount of codes I normally have though. Also I bought an edge cts3 tuner just for the extra gauges and what not, and it would not stay connected to CAN.

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Friday, July 4th, 2025 AT 9:43 AM

STEVE W.

MECHANIC
14,727 POSTS

The description sounds like a bad main power connection. When it's cold it fails because it shrinks, then as it warms up and expands it "repairs" itself. That would cause your faults as the modules turn on and off with the power. The problem is isolating where the issue is. The truck starts and runs fine regardless of temperature, or does it not start in the cold? It sounds like something in the body module harness or in the cluster itself, like a corroded ground or bad connection. Especially with all the low battery and comm codes and the dash rebooting on its own. Did they replace the battery? Do you have a list of what they did, or did they just say they went through the harness?

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Friday, July 4th, 2025 AT 11:24 AM

REGGINA

MEMBER
5 POSTS

Yes it always starts and runs regardless of the temperature. I put a new battery in less than a year ago. The pictures I posted of the diag report were from a while ago; it's still throwing the same codes besides the battery/voltage. I can maybe find the paperwork, I know they did the ignition switch, advance Trac module or whatever the proper term is, 4WD module or t-case, BCM and went through my wire harness.

Ford website just says "Vehicle serviced drivability/performance checked"

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Friday, July 4th, 2025 AT 12:08 PM

STEVE W.

MECHANIC
14,727 POSTS

Yeah, it sounds like the read the codes and swapping parts, not really the best way on these issues. Being it starts and runs the issue likely isn't under the hood, I would lean more toward a bad cluster that has a bad solder joint or two. That is a common failure mode. Hard to test though unless you pull the cluster out, take it apart and use a microscope to check the board and flow some new solder to repair it.
You might look at jeffescortlx and MaicSalazarDiagnostics on you tube to get an idea of the process. They both do repairs as well and might confirm the fault if you contact them.

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Friday, July 4th, 2025 AT 6:01 PM

REGGINA

MEMBER
5 POSTS

I appreciate your help; I am going to get in touch with them or another cluster repair business. Speedo needle is 20 MPH off anyway; it has needed to come out for a while.

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Friday, July 4th, 2025 AT 7:10 PM

STEVE W.