Upgrade 3 to 3.4 working but found a few bugs

Hello, I did search on the forum before posting but want to make sure of what to do next. I have a US/NA 2016 F-150 with Nav that I upgraded from 3 to 3.4.20196. Everything seemed to be working great using the automatic configuration tool for windows. I did perform a master reset once complete and did not see any problems at first.

Issue 1: Heated/Cool seats not working. The seats have never been on my screen, including back on the OEM sync 3 dash prior to upgrading the usb ports and updating to add Carplay and Android Auto. I have physical buttons for my heated and cooled seats. The lights on the buttons turn on but the seats themselves never actually turn on. Normally you’d be able to hear a physical “click” when clicking them on from an off state or when going from on to off state. Since upgrading the lights turn on but nothing happens.

Issue 2: Apple Carplay randomly disconnecting. I was using my personal phone (synced with bluetooth and plugged in) for carplay and not having problems. Needed to make a work call so I switched to my work phone (not synced to bluetooth but plugged in on carplay) and in mid call it drops the carplay connection but the call stayed on. I reseated the cable and carplay came back but then got interrupted again a few moments later. Is the primary device trying to take over via the bluetooth or what is happening here? Did not have the problem previously on sync 3.0

What should I be doing to solve the issues? I am not looking to get buttons on the touch screen but if that’s required to get the physical switches to actually work again I’m up for whatever. Sidenote: I have not used forscan up to this point. Any help is greatly appreciated.

On number one, the apim has no effect on your heated seats. Is your ignition on when you try this? I’d recommend disconnecting your battery for 30 mins to see if that fixes it, otherwise check for DTCs. To reiterate, this is nothing to do with sync3.

On the second, replace your cable and clean your phone socket. Also try deleting your Bluetooth and carplay link and restart the pairing process from fresh.

So the heated/cooled seat control going out after the upgrade seems very odd. Is it possible there is some soft link there that was just interrupted and caused an issue, meaning a 30 minute battery reset would solve that? is that what you are suggesting? Just trying to make sure I understand.

I actually just put a new cable in a few weeks ago. But the bluetooth and setup on the devices maybe be conflicting so I’ll try clearing them both and removing settings on the devices and resetting them up again.

The heated seats are controlled by either the body control module (BCM) or on some vehicles by a dedicated heated seat module (HSM). taking the battery off will restart all modules. The bcm is live at all times with the battery connected. A restart may fix it, else next step is check for DTCs.

I’ll go disconnect it now to give it a try.

That did not work with the seats. What are the DTCs

Run forscan and click the DTC button

Can you confirm you have the engine on while trying to turn the seats on?

I have never used forscan, I am assuming I need something to plug into the truck, I have an Iphone and Windows PC, is there something easy to find to use for that?

If you can confirm my question about running the vehicle with the engine on it would be appreciated.

You’ll need an OBD USB scanner, recommend you do some research on the Forscan website to understand the product.

Oh yeah, the truck is running when I am trying. I checked the heated seat fuse under the hood, i think it was #17 and it looks fine. So i’ll have to get a usb to check that and look into forscan

Do the physical seat buttons work? You hear the click?

Physical buttons light up, No click. Both drivers and passengers heat or cool option light up but do nothing, with the truck on. Just was outside and found no fuses broke and no evidence of burning/shorting out, checked connector under seat and see nothing bad. Checked owners manual and verified several fuses both under hood and inside truck that could potentially cause issue.

I am starting to get more of a software issue vibe as both sides stopped working at the same time. I did order a usb cable for forscan today, should be here friday.

Both seats environmental controls (heating and cooling) are controlled thru the SCME module under the passenger seat. They are primarily controlled thru the FCIM (the panel with the buttons) sending messages over canbus to the SCME. The APIM can also send the same messages, they work in parallel. There is nothing that the update to the Sync system would have done that would cause the issue you are experiencing with the seats. One thing that will cause the seats to stop working is a DTC in the SCME module, which will disable the module until cleared. This is a safety thing in case the module was defective. When you get a DTC reader, look for DTC’s in the SCME, BCM and APIM.

Remove phone from Sync, master reset the APIM, let it boot back up. While that is going on, delete the bluetooth connection for the truck, reboot your phone. Once everything is rebooted, add the phone back to the truck, turn on notifications on the phone. Make sure the ringer is set for “Use phone ringer” in Sync.

Ahh, I was looking under the drivers seat at that module. I inspected the passenger side and yes. It has that burnt pin issue I’ve seen searching online. Crazy timing to happen with the week of me doing the sync upgrade. Hopefully my extended bumper to bumper warranty covers the issue.

Thank you to both of you for the support!

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The burnt pin on the SCME is a common fault. Now that winter is approaching and cooling down, folks are finding it. Here is the doc on the repair if they don’t cover it.

SCME Ground Wire Modification.pdf (1.2 MB)

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Sync 3.2+ is a bit different the way it handles BT and CarPlay (Sync 3.0 does not have CarPlay). Both phones should be added to the system and one phone should be the default phone. When in CarPlay mode, the phone connected will keep trying to add itself to BT if not added already, hence the disruption. I found this on the Ford how to videos…

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This makes sense for the most part. I definitely had CarPlay on newer versions 3.0 but had to change the USB and update software from the base system to enable the feature. However, if the way it handles BT and having defaults on that behavior it would make sense as the 2nd phone it was unpairing from CarPlay while in use because I didn’t have BT setup yet on that phone yet but did with my main phone. I’ll make sure both are setup in the future.

Thank you for the tip!

Yep. You are welcome.

Did you resolve the seat issue yet?

Dealership appointment is Ina few days. Called on my extended warranty and it should be covered.

Excellent. Let me know what they do, just curious…