Sync 3.4 to Sync 4 swap. So close, but so far

Ford Non SYNC 3 Support
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Recently swapped from sync 3.4xxxx to sync 4 and 12" screen in my 2019 f250 lariat. I bought the FordSync4 kit secondhand, so I had expected a need for forscan adjustments. HVAC module is 21-23 f150 w/ heated steering wheel button, h/c seats. Factory B&O system.

I’ve spent hours, and have gotten it mostly operational.

Current issues (some highly typical) are:

No ford pass

No nav functionality, but I do have maps available and fixed my locator from doing the hula.

A few hvac codes which appear related to pinning of the humidity/cabin temp sensor. From what I’ve read is re-pin and use a 21+ f150 sensor.

Presets don’t actually save.

Xm works

RCM code saying can’t locate apim

DSP code stating invalid or missing FCIM (can’t remember the exact wording)

APIM code saying incorrect display hardware

My big questions…I’ve looked, I’ve searched, I’ve read, and I’ve done a few very successful sync 2-3 conversions using sourced hardware and as-built sheets, not an ordered kit, added factory powerfold boards with a custom built harness that pins into the cab harness, and a buddy now sells…are:

Where do I plug what in where, as far as antenna or fakhra cables? I wasn’t totally sure and can’t find anything anywhere.

How could I get ford pass working?

Map function working?

The few aboves?

What hardware, software, can translator? - and please explain on that last one. I’m a smart cookie, but that last one’s not my fortee- yet.

One leftover dtc or loose end is gonna bug the crap out of me. It already bugs me that I can’t just pull up the HVAC module. If I can add that, too - I’ll deliver a bottle of whiskey myself, lol.

I realize this is a bit of hand-holding, but I’ve searched, and am stuck a bit. Thanks whomever in advance.

Oh, and you’re welcome for the air freshener idea. It’s Apple Cinnamon. :smiling_face_with_sunglasses::laughing:

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There is a trick to getting FordPass to work in a Sync 3 vehicle with a Sync 4 APIM, which is to reinstall the Sync 3 APIM and activate it, then replace it with a properly configured Sync 4 APIM and hopefully the TCU ESN shows up. However, as soon as you do any APIM reset it will stop working. So pretty useless.

Nav and Sync 4 cannot be updated, you are stuck where you are unless someone releases a method to do it outside of FDRS. If you have maps on the Sync4 APIM, that’s what you’re stuck with.

The HVAC module should just work with Sync 4, as long as the wiring is correct and you can see it in FORScan. In Sync 4 you should have full functionality, but being this is in a 2019 F-250, maybe some restrictions.

Presets: make sure the original ACM is X40 capable, Sync 4 works best with the newer Sirius XM platform. Also make sure the preset mode is the same in the APIM and ACM.

The RCM has issues with this upgrade, many people have had this issue. Might be asbuilt but in some cases never resolved. Make sure both modules are seen in FORScan. Create a new profile in FORScan to discover all the modules and make sure the OEM modules are updated.

Fakes cables for what specifically?

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Sadly there will be some you will have to live with.

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Absolutely. Even with Sync 3 swaps or other module upgrades this is inevitable.

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This might be a bit harder. Your truck has a K series TCU that runs on HS3. The Sync 4 modules will look for the TCU on both HS4 and the new Ethernet wires(Mainly for OTA updates) through the GWM. Without adding a newer TCU & GWM I dont think this will work right with the APIM.

The K series could be changed to work on HS4 but the rest would still need to be done. No garentee this would work but I think it’s the only way.

I dont know of a Sync 4 system that uses anything other than HS4 for the TCU. The APIM only has HS3 going to it on Sync 4 so it would come down to the GWM.

The communication paths are very different from CEGA 1.3 to the new Sync 4 setups.

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Thanks for the prompt responses. On the ACM, there was a black and a yellow cable that I might be assuming were both GPS or antenna cables. I’m now assuming one might be the a2b for the b&o. The sync 4 apim has 2 blue and a tan/yellow, two of which are populated.

I did read on reinstalling sync 3 - which also brings fordpass back, but I was hoping for hardware to do that.

I did notice on the RCM: I had to disable the passenger airbag indicator on CAN. However, there’s also a “indicator present” as-built they needed to be disabled, or id have an airbag light. When I turn that off, I get the apim code. On, indicator MIA code. :person_shrugging:

I’ll recheck ACM, APIM, and DSP info for the XM stuff. And I’ll verify hardware numbers.

Any insight on the canbus translator? That appears to be what they’re including in the new kits, which supposedly fixes everything. It seems as simple as hs3 talking to hs4 and vice versa via gizmo; it’s probably way more than that.

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I’m more than willing to try. It appears TCUs are fairly inexpensive, but I’m honestly not sure which one to source. Id do the whole shebang if I knew it’d work. A yard on eBay has all of the modules out of a 2022 f250 lariat on eBay currently for $300, tcu, gwm, and bcm included. If I had the resources for pinouts, etc, I’d be waiting by my mailbox.

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I belive it will be far more than that. It’s a huge rabbit hole.

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Don’t bother with replacing the TCU, it won’t work due to restrictions in Ford servers….

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