We've been having some weird intermittent electrical issues on our 2015 Lariat and I'm thinking that it may be the FCIM. Was hoping to get some input here before I go ahead and try to order a replacement.

These are the symptoms I have observed (they were intermittent but now seem to be permanent):
- No HVAC
- Front seat heaters/cooling not functioning (rear seat heaters work)
- Can't operate the front power windows from the drivers side master window control. The back windows will operate from the drivers control and the front passenger window will operate from its local control.
- No controls on the center console work except for the buttons on top for the hazard lights, hill descent, etc. but those don't appear to go through the FCIM board.
- Touch screen works, but unable to turn on HVAC, seat heaters, or heated steering wheel from it.
- Can still control audio from steering wheel controls and touch screen.
- Blind spot detection doesn't work.
- Navigation doesn't work.
- Cross traffic alert doesn't work.
- No outside temperature displayed on the touchscreen

I temporarily removed that entire front panel and nothing seemed to operate any differently.

 

Your problem is likely the MS-CAN bus. This is typical of a taillamp assembly that is leaking water. It gets into the electrical connector that is inside the taillamp and connects to the SOD (Side Object Detection) module (aka: BLIS module). You need to check the taillamps and the SOD electrical connectors. The following modules all use the MS-CAN bus:

• RTM
• TRM
• DDM
• HSWM
• GPSM
• FCIM
• PDM
• DSM
• SCME
• PRB
• SODL
• SODR

 

Is the taillamp leakage a common issue leading to these types of symptoms?

Is there anything I could learn via an OBD2 scan?

 

This is a common problem with your symptoms. An OBDII reader likely will not read DTCs from the modules you are having problems with. You need to scan with FORScan or a diagnostic scan tool. There are many threads on this forum dealing with this.

 

Holy crap that was it! Thank you!!!

Took one of the rear taillights off and it was full of water. As soon as I disconnected it everything worked!

Just when I thought the internet had no redeeming positive qualities...

 

You're welcome.

 

Leaky taillights seems to be very common on the 13th gen trucks. Already replaced one and the other one is getting water in it. Luckily for me I have the old bulb type taillights and they're only $80 for a OEM replacement. Wait until the OP finds out how much the LED BLIS units cost.

 

Thank you for posting this!!!! My 2015 Lariat did the EXACT same thing. I've been driving it for a little over a month this way because I just invested 2k in other repairs. It allowed me to drive but had all the faults including the front windows not working. It would cycle in and out intermittently. I have a friend from F who I finally asked about it and he mentioned FCIM possible replacement. I did an online search and your post came up. My driver's rear light was full of water. I emptied it and dried it and now all the faults went away!!!!! Thanks again!!!!

 

Thank you for posting this!!!! My 2015 Lariat did the EXACT same thing. I've been driving it for a little over a month this way because I just invested 2k in other repairs. It allowed me to drive but had all the faults including the front windows not working. It would cycle in and out intermittently. I have a friend from F who I finally asked about it and he mentioned FCIM possible replacement. I did an online search and your post came up. My driver's rear light was full of water. I emptied it and dried it and now all the faults went away!!!!! Thanks again!!!!

 

Older thread, but was hoping to get some insight on a similar issue. Recently picked up a used 2022 F350. It's currently in the barn getting some TLC, and I'm experiencing FCIM issues (it's not being read/connected in Forscan and the panel does not function to touch).

Similar to your post about water intrusion into the MS-CAN BUS system... do you know if the system gets angry if/when the rear harnesses are disconnected? I have the bed off the truck right now to do some work on the frame/hitch. So, the rear harnesses (at the bumper) are all disconnected. Will that be enough to disrupt the system and cause my FCIM issues? NOTE - I never pulled the FCIM/radio panel. I DID change the gauge cluster (upgraded from the standard XL to the 4.2" XLT screen) and made some tweaks in FORSCAN to accommodate the new gauge setup, tire sizes, door keypad, etc. But my FCIM buttons are illuminated, the radio plays and can be controlled through the steering wheel controls. But, none of the FCIM buttons (radio or HVAC) work.

Thanks - feel free to PM me if needed.