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2025 Blind Spot Monitoring and Automatic Emergency Braking related changes

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cyclopsdiver

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After conversing with another owner who installed a flatbed on the other forum, it seems his Automatic Emergency Braking, Lane Keep Assist and ACC are inoperable with his factory taillights and rear sonar unplugged. I am experiencing the same condition however I additionally have a lift installed, the steering wheel has not been centered yet so I'm sure the Steering wheel position sensor is throwing an error and my front parking sensors are also unplugged. The 2021 did not exhibit similar faults so it seems the computer programming disables the forward-facing safety features if BSM is unplugged. Another change I noticed is I had the flatbed lighting run through the 7 pin plug on the 2021 and the truck did not recognize a trailer plugged in with just the lighting and no brake wire plugged in. The 2025 does and disabled the rear park sense, so I will need to find an alternative wiring method.

Also the taillights appear to have a new sensor in them, I have attached some photos. What looks interesting is the lack of any weather seal around the housing or sensor where they meet. Hopefully the BSM opening is sealed internally from the LED's. I'm hoping that the sensor itself is potted and weatherproof allowing for a simpler retrofit into the flatbed to regain forward safety/radar related features.

@Jimmy07 if you have any insight I'd surely appreciate it.
 

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Making some headway. The upfitter passthrough wiring has changed slightly for 2025 and there are still no new documents on the Body Builder site to reference. The white upfitter connector next to the parking brake which feeds the blunt cut wires above the spare has a slightly different pin layout.

I depinned the taillight housing wiring from the Molex 150 connector and plugged the BSM sensors in, temporarily zip tied under the flatbed. Regained cruise control, adaptive steering, and emergency braking. The only Message I get now is Lane management is limited due to BSM being unavailable. I can't wrap my head around why Ram would disable all forward-facing safety features due to BSM being unplugged.

I am also unable to activate front or rear wig wags using the VSIM and grounding pin 11 or 14 on the black connector. The VSIM document was one of the few available for the 2025 D2 however it looks to be recycled from 2019+, I am unsure if there are any changes that were not updated or why the wigwag won't function on my truck.
 
You need to wait for AlfaOBD to be compatible with the 2025s to disable BSM and leave everything else alone. That way nothing is just "unplugged' .
 
sstoner911 said:
You need to wait for AlfaOBD to be compatible with the 2025s to disable BSM and leave everything else alone. That way nothing is just "unplugged' .
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I didn't want to wait that long without cruise control and lane assist. I'm also just documenting the differences I've found. I'm hoping to get some brackets fabricated to reinstall the BSM sensors in the flatbed and regain full functionality. And who knows if AlfaOBD will be able to fully disable it, the logic on the 2025 is obviously different and BSM is tied to cruise, lane keep assist and emergency braking. I understand it could have removed the BSM message on my 21, but I also didn't lose any functions having it unplugged.

Still not sure why I can't activate the wig wag using the VSIM. @Jimmy07 if you have access to any other documents or wiring diagrams that disagree with the 2025 VSIM doc on the body builder site that would be helpful. Maybe they changed the pin which activates it or made it a 12v+ trigger instead of ground, but I don't want to just start sending 12v to random pins on the VSIM and damage anything.
 
cyclopsdiver said:
I didn't want to wait that long without cruise control and lane assist. I'm also just documenting the differences I've found. I'm hoping to get some brackets fabricated to reinstall the BSM sensors in the flatbed and regain full functionality. And who knows if AlfaOBD will be able to fully disable it, the logic on the 2025 is obviously different and BSM is tied to cruise, lane keep assist and emergency braking. I understand it could have removed the BSM message on my 21, but I also didn't lose any functions having it unplugged.

Still not sure why I can't activate the wig wag using the VSIM. @Jimmy07 if you have access to any other documents or wiring diagrams that disagree with the 2025 VSIM doc on the body builder site that would be helpful. Maybe they changed the pin which activates it or made it a 12v+ trigger instead of ground, but I don't want to just start sending 12v to random pins on the VSIM and damage anything.
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I looked in to maybe fabricating something for my flat bed, the my bed is it would be a lot of work and I am not a "need" BSM kind of person I guess. They certainly changed he design of the BSM sensor. I have a buddy who bought a new 2025, he hooked his radar detector to the review mirror harness with an adapter just like in his 2020 3500 - the truck did not like that and threw all kinds of dash lights and errors. The 2025s seem really sensitive to electrical changes.
 

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Any solution to this yet? I have a deposit on a flatbed for my 25' 3500 Laramie. Planning on installing in a couple of weeks.
 
NCRAM3500 said:
Any solution to this yet? I have a deposit on a flatbed for my 25' 3500 Laramie. Planning on installing in a couple of weeks.
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Unless you want to deal with error messages I would not do a flat bed on a 2025 with blind spot anytime soon. How long - who knows with this new computer architecture in the 2025s...
 
NCRAM3500 said:
Any solution to this yet? I have a deposit on a flatbed for my 25' 3500 Laramie. Planning on installing in a couple of weeks.
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Post in thread '2025 Limited Matte PPF, Crystal Granite Metallic, 37s, Carli Pintop, Flatbed' https://hdrams.com/forum/index.php?...ic-37s-carli-pintop-flatbed.19574/post-347452

I posted an update in my build thread. I ended up cutting holes in my CM flatbed for the BSM sensors. The skirting is not the exact angle of the sensor as in the taillights but it does not seem to impact functionality and I have cruise and emergency braking back.

The vsim document has not been updated for the 25+ trucks last I checked. Ram body builder support finally confirmed the wig wag feature was changed from ground input to 12+ and I got it working.
 
cyclopsdiver said:
Post in thread '2025 Limited Matte PPF, Crystal Granite Metallic, 37s, Carli Pintop, Flatbed' https://hdrams.com/forum/index.php?...ic-37s-carli-pintop-flatbed.19574/post-347452

I posted an update in my build thread. I ended up cutting holes in my CM flatbed for the BSM sensors. The skirting is not the exact angle of the sensor as in the taillights but it does not seem to impact functionality and I have cruise and emergency braking back.

The vsim document has not been updated for the 25+ trucks last I checked. Ram body builder support finally confirmed the wig wag feature was changed from ground input to 12+ and I got it working.
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On my 2024 the BSM sensors were wired in to the taillight wiring,looks like that changed for the 2025s? I used AlfaOBD to turn off the BSM. I am not sure I am to worried about getting it back. I was not to sure how to seperate the BSM sensor from the taillight housing.

I also wasn't sure how weather proof they are- probably was going to need a fabricated housing for them.

20250212_070610.jpg20250212_070635.jpg20250212_071127.jpg
 
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sstoner911 said:
On my 2024 the BSM sensors were wired in to the taillight wiring, is that the same for the 2025s? Can you give some insight as to how you wired them. I used AlfaOBD to turn off the BSM. I am not sure I am to worried about getting it back.
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On my 21 I just left them unplugged and ignored the single popup saying it's disabled, but there is nothing available for the 25s to disable it and if the sensors are not plugged in you lose cruise control, emergency braking, 4wd and the truck gets very angry.

I ordered these 12pin molex connectors and depinned the tail light, used the extra wires to run the flatbed lighting

 
cyclopsdiver said:
On my 21 I just left them unplugged and ignored the single popup saying it's disabled, but there is nothing available for the 25s to disable it and if the sensors are not plugged in you lose cruise control, emergency braking, 4wd and the truck gets very angry.

I ordered these 12pin molex connectors and depinned the tail light, used the extra wires to run the flatbed lighting

Click to expand...


It certainly is far more complicated on the 2025s.
 
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