Class Action Lawsuit - Home Integration System

[Jim Lewis]

Right.
But if you do that during a grid outage the inverter is off and you're done until the grid comes back up.

OK. I didn't understand the context in which you were talking about rebooting the HIS system and wanting to shut down the Dark Start battery.

I don't think the truck going to sleep per se is the problem. I've had the truck asleep, simulated an outage plenty by cutting grid power, had the port light come on, heard relays clicking in the truck with the FCSP LED turned green, and have the white port light go out after ~30 sec with no power transfer from the truck activated. So, with my truck at least, I think a power loss can wake the system, but the communication needed for automatic power transfer is not working. If I do the UNLOCK button trick or start the truck and initiate manual power transfer, it's worked the last 4x in a row (2x via UNLOCK trick, 2x via SYNC screen manual transfer with truck running).

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[Steely]

OK. I didn't understand the context in which you were talking about rebooting the HIS system and wanting to shut down the Dark Start battery.

I don't think the truck going to sleep per se is the problem. I've had the truck asleep, simulated an outage plenty by cutting grid power, had the port light come on, heard relays clicking in the truck with the FCSP LED turned green, and have the white port light go out after ~30 sec with no power transfer from the truck activated. So, with my truck at least, I think a power loss can wake the system, but the communication needed for automatic power transfer is not working. If I do the UNLOCK button trick or start the truck and initiate manual power transfer, it's worked the last 4x in a row (2x via UNLOCK trick, 2x via SYNC screen manual transfer with truck running).

How long ago did you repair the system? Does it list the charger as Ford 3000 or the new name?

 

[Jim Lewis]

How long ago did you repair the system? Does it list the charger as Ford 3000 or the new name?

I have the latest inverter firmware ending in .36 and after the firmware update, I did have to repair the truck and the FCSP. The FCSP is now identified in the IBP app as "Ford Charge Station Pro 1." I repaired my truck and FCSP on 6/16/25:

https://www.f150lightningforum.com/...train-battery-parking-brake.24247/post-532696​

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https://www.f150lightningforum.com/...train-battery-parking-brake.24247/post-533040​

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and tearitupsports reply: https://www.f150lightningforum.com/...train-battery-parking-brake.24247/post-533045​

 

[Pitbull2o08]

I need to make a new thread but I was able to get mine working after 70 plus emails with Ford engineering.

I would say that if your truck hasn't gotten updates you should pursue with Ford BEV hotline getting an appointment at a dealer to fix whatever is preventing that. In my case the gateway module was stuck in a state where updates were off no matter the setting shown on screen.

Confirm the inverter is up to date. There were some fixes in the newest version. I think it was version x.x.36

But most importantly and what fixed it for me was a hardware install issue. At some point they changed the installation and no longer connect the common/ground on the rs485 port. Old installs have orange landed there but this screws the transfer up and causes it to hang and eventually fail. Sunrun tech lifted this orange and it transferred properly immediately after for me.

If your having what looks like good transfer but then no power followed by failure after 1 to 2 minutes check if you have this orange communication line landed, it should not be.
I'll add in a before / wrong picture for reference.

That info was given to me over a year ago. Sunrun disconnected that orange wire. Still a no go.

 

[v2h8484]

That info was given to me over a year ago. Sunrun disconnected that orange wire. Still a no go.

Not surprised that disconnecting the RS485 ground didn't work. RS485 on systems like this should really be fully isolated electrically. Otherwise it's relatively common to see comms problems due to noise or out of range common mode voltages. One potential fix is to add isolation using an external isolator. Keep in mind that you will need an external power source (e.g. a 5V or 12V battery) for the isolator.

 

[Steely]

Not surprised that disconnecting the RS485 ground didn't work. RS485 on systems like this should really be fully isolated electrically. Otherwise it's relatively common to see comms problems due to noise or out of range common mode voltages. One potential fix is to add isolation using an external isolator. Keep in mind that you will need an external power source (e.g. a 5V or 12V battery) for the isolator.

Nevermind mine isn't working again. It's been 50 days since they disconnected that com wire, it worked 4 or 5 times in test shortly after, I ran it for 8 hours one test, but now after sitting it's back to the same failure mode - looks like it transferred but not actually powering the house for 90 seconds then a charger fault.

 

[Jim Lewis]

Nevermind mine isn't working again. It's been 50 days since they disconnected that com wire, it worked 4 or 5 times in test shortly after, I ran it for 8 hours one test, but now after sitting it's back to the same failure mode - looks like it transferred but not actually powering the house for 90 seconds then a charger fault.

Google Gemini and ChatGPT 5 have some very interesting things to say about this. They both agree that lifting the orange RS485 ground wire is a good idea, as it removes a shared ground between the truck and FCSP, which can be a source of problems if there's a Ground Potential Difference (GPD) in the system. But they say that removing the FCSP RS485 ground connection is likely treating a symptom, not the cause itself, a GPD problem on the FCSP/HIS side, which can come back to haunt you. I have miles of dialog shared between the two agents, along with a very detailed electrical troubleshooting guide created by ChatGPT 5, which Gemini agrees is excellent. I could provide it as an attachment or DM it to you, @Steely, if you think it might help, or you could chat with these agents directly yourself.

BTW, I notice that the orange ground is still shown as connected in the FCSP on the Sunrun field website wiring diagram instructions. Sunrun hasn't bothered updating that diagram, even if leaving the orange ground disconnected is now accepted as the better option!



Actually, the orange ground wire only seems to appear in systems that have an ESS (Energy Storage System = wall battery): (upper right of following diagram)



Around 2'41" into the following Sunrun wiring verification video, it shows that the A8 RS485 connector in Steely's BEFORE picture is not wired in Home Integration Systems that only have the Lightning as a DC power source with no ESS or PV source.

 

[tearitupsports]

Google Gemini and ChatGPT 5 have some very interesting things to say about this. They both agree that lifting the orange RS485 ground wire is a good idea, as it removes a shared ground between the truck and FCSP, which can be a source of problems if there's a Ground Potential Difference (GPD) in the system. But they say that removing the FCSP RS485 ground connection is likely treating a symptom, not the cause itself, a GPD problem on the FCSP/HIS side, which can come back to haunt you. I have miles of dialog shared between the two agents, along with a very detailed electrical troubleshooting guide created by ChatGPT 5, which Gemini agrees is excellent. I could provide it as an attachment or DM it to you, @Steely, if you think it might help, or you could chat with these agents directly yourself.

BTW, I notice that the orange ground is still shown as connected in the FCSP on the Sunrun field website wiring diagram instructions. Sunrun hasn't bothered updating that diagram, even if leaving the orange ground disconnected is now accepted as the better option!



Actually, the orange ground wire only seems to appear in systems that have an ESS (Energy Storage System = wall battery): (upper right of following diagram)

A ground is not needed for the serial communication. I just use 2 wires twisted together using a drill for the communications which has been flawless on my system. The EN and GRD for the lg battery is a 12v signal and has nothing to do directly with the RS485. They just happen to use the same terminal block.

 

[Jim Lewis]

The EN and GRD for the lg battery is a 12v signal and has nothing to do directly with the RS485. They just happen to use the same terminal block.

Here's what ChatGPT replied much earlier in the day as to how GPD problems in the ESS RS485 connection could indirectly affect truck/FCSP handshaking. I always mistrust AI advice from any source. I've found it can be flagrantly wrong but often it at least points me in the right general direction to a better understanding of important variables in a situation.

Yes — if the ESS ground is bonded into the FCSP, its ground potential difference can indirectly affect the truck connection, because the FCSP is the bridge point. That’s why installers saw short-term improvement by floating the ESS comm ground, but long-term reliability requires addressing the actual GPD (bonding practices, isolation, or surge/noise management).

And a further ChatGPT answer made in direct response to feeding it the first quote in this post:

Could the 12 V GRD from the ESS still cause trouble?

Yes — even though it’s “just” a logic ground, it’s still a galvanic connection between the ESS’s low-voltage domain and the FCSP’s logic ground. That means:

• Any ground potential difference (GPD) between the ESS chassis and FCSP chassis will show up on that 12 V ground wire.
• That offset can couple noise into the RS-485 transceiver if the board doesn’t keep the domains well isolated.
• It won’t directly shift the RS-485 A/B voltages (they’re differential), but it can:
  • stress the isolation barrier,
  • cause common-mode noise,
  • or trip faults if the ESS logic ground drifts relative to the FCSP ground.

So the forum member is right: it’s not technically the RS-485 reference. But yes — the ESS ground still matters, because once it’s tied into the FCSP logic board, it can influence other comms and even the PLC handshake with the truck.

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