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Overall I am quite pleased with the workmanship and quality. I have off-roaded it and everything mechanical is solid and well done and the truck runs and drives great. Things could have gone better, though.
What follows is a moderately unhappy story.
I originally sent the truck to MegaRexx in Tuscon, who built virtually every other MegaRexx out there. Anyway, the owner sold the business and MegaRexx name to guy out in Wilmington. My truck was one of the first ones finished by the new owners in Wilmington. It did not go smoothly between the new owners and old owners, though it was originally intended to be a harmonious transition. This headlight issue was not brought to my attention until I took delivery of the truck and I didn't really think to check the headlights... cause you just assume they worked that out. I am mechanically and electronically inclined so I am handling it because they were not willing to figure it out. I would rather just do it myself or with local off road shops I trust at this point. I think I will ultimately ask the new owners to settle up with me as this is not the only issue I am resolving, some of which I am doing through my local Ford dealership I bought the truck at. It is almost all small stuff, but the attention to detail on some of this stuff just wasn't there. It is definitely not the way you would hope things would go, they got it 90% right and seem to have only missed on details... but, as you implied, when you spend this kind of coin you expect everything to be just right. The other list of issues is worthy of its own post. (Like, why they could not figure out the pre-collision / adaptive cruise radar calibration issues, despite allegedly hiring a Ford tech with proper VCM/Ford diagnostic software and F250 knowledge, here is a hint... the sensor has to be perfectly level, lol). They also fried the BCM and had to replace that, causing a 2-3 week delay on the build because it was throwing power train codes and such, but it was all in the BCM as far as I could tell. The new shop should have communicated these minor issues and done more to resolve them with me. They were also like 2-3 months behind schedule, I wanted it done.
Ultimately, I think this split and loss of institutional knowledge from the old MegaRexx team greatly contributed to a lot of my minor issues. I am a pretty understanding person and I just wanted the truck back. The remaining issues were all things I knew I could handle locally. The end.
Understood. I hope you can get it where you want it. It is an awesome looking truck. Enjoy!!
I cheated and acquired a copy of the official Ford shop manual. In case anyone wants the definitive answer, here it is:
Acronyms:
SCCM = Steering Column Control Module
LH = Left hand
GWM = Gateway Module (A) -- a little control module under the dash
BCM = Body Control Module
CAN* = CAN bus nonsense
LIN Circuit = https://en.wikipedia.org/wiki/Local_...onnect_Network -- a well known serial protocol (similar in concept and usage to SPI, I2C, etc... but obviously automotive industry has a different thing because of course they do)
"""The SCCM monitors the LH steering column multifunction switch for a high beam request. When the LH steering
column multifunction switch is in the HIGH BEAMS position, the SCCM sends a message over the HS-CAN2 to
the GWM , then the GWM sends the message to the BCM over the HS-CAN1 .
The BCM supplies voltage to the LED control module mounted on each headlamp assembly when the ignition is
on.
When the BCM reads a request for the headlamps on, it sends a message through the headlamp LIN circuit to the
LED control module mounted on each headlamp assembly. The LED control module then provides the proper
voltage to the high beam LED in each headlamp assembly.
When the low beams are on and the BCM receives a request for high beams, low beam Light Emitting Diodes
(LEDs) remains powered on and the high beam Light Emitting"""
In plain English the BCM uses a serial protocol to talk to the LED lamps and tell it to use high beams. E.g. high beams by wire, as we suspected.
Given that this is an industry standard protocol parsing it would not be too hard. There are Arduino and other CAN/LIN development kits, so making a prototype would not be hard. So, in my situation, if you wanted to do this at the headlamps, basically, you would need to find the LIN network wire going into the LED headlamp assembly (this manual is huge, I am sure there is a pin out for it somewhere in here) and spy on it with a logic analyzer to figure out the exact LIN messages being sent. You can then interpret that serial protocol and using a relay when you find the high beam request signals, power a headlamp circuit separately.
I cheated and acquired a copy of the official Ford shop manual.
Not cheating, wish I had access to official Ford shop manuals.
This is great research and confirms our suspicions. Next step? Time to buy a bunch of Raspberry Pi's and Arduino boards! My career is in IT and I've written tons of automation for various cloud based services, including Alexa skills and home automation frameworks that I've deployed to Pi's (things like HASS, MQTT, etc.). Learning the LIN Circuit protocol probably wouldn't be that difficult and is the only questionable piece of this puzzle. But as fascinating as this project would be, it would likely take me multiple weeks to work out just due to having a busy schedule. Although I think I have a spare Pi and Arduino board laying around...
I will update this thread if I decide to dig into this. I am currently also trying to locate the high beam switch in the cabin to see if I can save myself some heartache. I think there may also be a sort of short cut that I will investigate. As I review this thing manual (It is over 15,000 pages) it seems there are a number of other components that get informed about high beam / low beam status. Some of those might be simple voltage on/voltage off wires. That would trivialize tying into them and may be more convenient than the steering column selectors switch approach I outlined.
As far as the signal analysis goes, a good logic analyzer combined with the documented nature of the LIN protocol should make reversing it pretty simple. If you really get into this just update this thread and I should have a my head around this (massive) manual by then and can update / provide details from there.
It all works on my truck fine (2021 Platinum). I don't have time to write everything up, but this is also all rather easy to do with a couple of YouTube videos and some patience. The short version of the solution: Install a thing that listens on your CAN bus, it will detect when high beams are "on". It will then fire up a low current output and you can use that to fire a relay. Wire up whatever you want on that circuit (in my case, high beams, but people apparently use these for off road upfitting, etc). The end! Short and sweet, it just works.
I personally had never wired up a relay, but that was easy. Here are my notes and choices I made for wiring everything:
1.) To power the can bus snoop device, I used a fuse tap thing on the adjustable pedal (always on) fuse. That is the only power for low current side of the setup. Easy enough. This is a tiny microcontroller that sips power, so most fuses will do. It has an auto-off feature and shuts itself down.
2.) The contactless reader goes on your medium speed can bus wires from your gateway port (e.g. the back side of your OBD-II harness). Since I had an amp step those two wires were already tapped and I had a nice easy place to install the contactless reader already. (AMP steps do a similar thing, but for door open and close). Please double check what I am about to write for your truck, but... GY-OG (Grey Orange) wire on my ODB-II harness is Medium Speed Can High and Violet Orange (VT-OG) is medium speed can bus low. This is the bus where lighting nonsense lives. You should find this on the wiring harness on the backside of your ODB-II port. I think you could also tap into your ODB-II port and not fiddle with the wiring back there at all if you needed to, but mine were already tapped with the AMP STEP Kit... some "posi-tap" thing. AMP ships them in their install kits and they seem fine, I didn't install my AMP steps. I also verified all my wiring with the shop manual I purchased.
3.) Wire up a circuit. In my case high beams are ~10 amps at full tilt, so I wired up my own 15 amp circuit direct on the battery with an inline replaceable fuse. I routed the wire to do its thing and reach the relay. The relay then powered the lights. Basic relay implementation, nothing fancy. I ran the small output wire from the can bus snoop through the firewall on my hood release since I no longer have a hood that uses a release, but getting through the firewall isn't hard, plenty of good routes to do it, including the official port for the wiring harnesses.
4.) That's it really.
The company that builds these modules, Canm8 builds modules for other purposes as well that could be fun and useful for folks upfitting, so I recommend googling them and checking out their product line. I have only had it for a day, but it all seems to work so far!
Probably took me like 10-12 hours because I took my time, soldered and shrink wrapped every connection, loomed everything with proper automotive looming tape and or looming harness things. Plus I had to learn and do a little research here and there.
It all works on my truck fine (2021 Platinum). I don't have time to write everything up, but this is also all rather easy to do with a couple of YouTube videos and some patience. The short version of the solution: Install a thing that listens on your CAN bus, it will detect when high beams are "on". It will then fire up a low current output and you can use that to fire a relay. Wire up whatever you want on that circuit (in my case, high beams, but people apparently use these for off road upfitting, etc). The end! Short and sweet, it just works.
I personally had never wired up a relay, but that was easy. Here are my notes and choices I made for wiring everything:
1.) To power the can bus snoop device, I used a fuse tap thing on the adjustable pedal (always on) fuse. That is the only power for low current side of the setup. Easy enough. This is a tiny microcontroller that sips power, so most fuses will do. It has an auto-off feature and shuts itself down.
2.) The contactless reader goes on your medium speed can bus wires from your gateway port (e.g. the back side of your OBD-II harness). Since I had an amp step those two wires were already tapped and I had a nice easy place to install the contactless reader already. (AMP steps do a similar thing, but for door open and close). Please double check what I am about to write for your truck, but... GY-OG (Grey Orange) wire on my ODB-II harness is Medium Speed Can High and Violet Orange (VT-OG) is medium speed can bus low. This is the bus where lighting nonsense lives. You should find this on the wiring harness on the backside of your ODB-II port. I think you could also tap into your ODB-II port and not fiddle with the wiring back there at all if you needed to, but mine were already tapped with the AMP STEP Kit... some "posi-tap" thing. AMP ships them in their install kits and they seem fine, I didn't install my AMP steps. I also verified all my wiring with the shop manual I purchased.
3.) Wire up a circuit. In my case high beams are ~10 amps at full tilt, so I wired up my own 15 amp circuit direct on the battery with an inline replaceable fuse. I routed the wire to do its thing and reach the relay. The relay then powered the lights. Basic relay implementation, nothing fancy. I ran the small output wire from the can bus snoop through the firewall on my hood release since I no longer have a hood that uses a release, but getting through the firewall isn't hard, plenty of good routes to do it, including the official port for the wiring harnesses.
4.) That's it really.
The company that builds these modules, Canm8 builds modules for other purposes as well that could be fun and useful for folks upfitting, so I recommend googling them and checking out their product line. I have only had it for a day, but it all seems to work so far!
Probably took me like 10-12 hours because I took my time, soldered and shrink wrapped every connection, loomed everything with proper automotive looming tape and or looming harness things. Plus I had to learn and do a little research here and there.
So now we know! The end.
hate to beat an old thread but I swapped 2020+ LED headlights and front flip to my 2018 super duty. All parts were from a 2021 platinum, and my truck is a platinum. Factory LED etc.
you think I could make this method work so I can activate the high beams on the 2020+ OEM LED headlights, from my 2018 truck ?
hate to beat an old thread but I swapped 2020+ LED headlights and front flip to my 2018 super duty. All parts were from a 2021 platinum, and my truck is a platinum. Factory LED etc.
you think I could make this method work so I can activate the high beams on the 2020+ OEM LED headlights, from my 2018 truck ?
So… this is a potentially very different beast. The 2017/2018 headlights are simpler. You power it with 12V, it makes light. That enables the simple relay set up to work. The new LEDs have a standard, but less common car networking protocol to control them. I can look things up in the manual again, but this will be an up hill battle and you will need different aftermarket parts. I think someone will have to reverse engineer the way the lights are set up. They don’t live direct on CAN bus. I am not 100%, but I don’t think the 2018 will interface with 20/21 lights.
So… this is a potentially very different beast. The 2017/2018 headlights are simpler. You power it with 12V, it makes light. That enables the simple relay set up to work. The new LEDs have a standard, but less common car networking protocol to control them. I can look things up in the manual again, but this will be an up hill battle and you will need different aftermarket parts. I think someone will have to reverse engineer the way the lights are set up. They don’t live direct on CAN bus. I am not 100%, but I don’t think the 2018 will interface with 20/21 lights.
im trying to figure it out. I’d like to have high beams at night. If not I may take the lights apart and see how they work internally. May be able to go around the ballast. If I’m right , only part of the LEDs light up on low beam , then all of them light on high beam command.
im trying to figure it out. I’d like to have high beams at night. If not I may take the lights apart and see how they work internally. May be able to go around the ballast. If I’m right , only part of the LEDs light up on low beam , then all of them light on high beam command.
That’s right. The lights always have power running to high and low beams. High beam signal goes CAN->LED micro controller->high beam enable. There may be something in between CAN and LED controller. That is why this will be tricky. The lights have a micro controller on them. Let me pull up the shop manual and tell you what Stock 21 looks like.
im trying to figure it out. I’d like to have high beams at night. If not I may take the lights apart and see how they work internally. May be able to go around the ballast. If I’m right , only part of the LEDs light up on low beam , then all of them light on high beam command.
Here is what I can tell you based on reviewing the shop manual and wiring diagram in addition to what I wrote above:
Key thing is on the LED diagram there is a "LIN" wire. That wire is how the BCM (Via the can bus) communicates with your LED control module. The BCM sends a message over the CAN BUS to the LED control module, which has its own "LIN" protocol somewhere in there to turn high beams off. Your only hope really is if you can bypass LED control module completely somehow, but I think that will be difficult. Otherwise you are in an awkward place of needing to do electrical engineering reverse engineering. While there is good tooling for it and I started doing it myself (I have some experience reverse engineering, including hardware, it is my profession), but it would still be very time consuming and doesn't make sense for us to even attempt. (Probably weeks of weekend and evening hacking for me). LIN /is/ a relatively simple protocol and there is tooling for it so you could in theory wire up a module that communicates with the LIN and it would not be too crazy. But you need a 21' with LEDs to make this easy so you can sniff its comms, record them, and then just replay them. I was on the other side of this trying to figure out how I might intercept these comms and power a relay when I realized there were off the shelf products doing this for us. I think if you can see an obvious way to power the high beams you should go for it. Otherwise I would just go after market if you want high beams and LEDs. Unfortunate, but that is where we are.
All that said, I have not looked into LED controller assemblies at all in the after market. There may be off the shelf upfitting modules that will speak to your simpler Halogen oriented setup and communicate to these LEDs. Some company may have already built out the hardware you don't have in your truck for upfitting these things. Good luck and let us know what you discover!
All attachments are for 21 Ford F250 but should apply to similar models (F150, F350):
im trying to figure it out. I’d like to have high beams at night. If not I may take the lights apart and see how they work internally. May be able to go around the ballast. If I’m right , only part of the LEDs light up on low beam , then all of them light on high beam command.
Final thought for you. You /can/ use the setup I mentioned to wire up a third party light. So you can use the CAN BUS sniffer to power a relay to power ... whatever you want. Including after market light bar or whatever to replace the high beams, but that is probably about as costly as just getting after market LEDs spec'd for your truck. That is mostly what these CAN BUS Sniffers are intended for (upfitting things to trigger on stuff like high beam signals on the CAN BUS, e.g. when you smack the high beams on your stalk).
Hey grog0x0, I read this thread a while ago and tried this canbus snooping device. Also been in talks with the guys through the link you sent and Canam8 who makes the device.
I have a new 2022 F350 with a January build date and the device did not work for me. My obd2 port is looking like not a true port and I would have to dive deeper somewhere into my dash to find the gateway module ( or smart data link module).
I have yet to find this module, possibly it's behind the 12" sync 4 display and center console...?
Did you tap into the wires behind the under dash port or did you have to go deeper? Any pics of your install?
Hey grog0x0, I read this thread a while ago and tried this canbus snooping device. Also been in talks with the guys through the link you sent and Canam8 who makes the device.
I have a new 2022 F350 with a January build date and the device did not work for me. My obd2 port is looking like not a true port and I would have to dive deeper somewhere into my dash to find the gateway module ( or smart data link module).
I have yet to find this module, possibly it's behind the 12" sync 4 display and center console...?
Did you tap into the wires behind the under dash port or did you have to go deeper? Any pics of your install?
Thx!
Hello. I find it hard to imagine Ford change their design of the OBD-II port under the dash very much. I have a wiring diagram for it, which I can dig up. I used a CANm8 contactless reader which fed into the thing. I have attached a couple of images. The one with my hand in it is over on the passenger side. The Canm8 lazer device gets can bus comm wires from the other image. It sits on the passenger side so it was easy to do a fuse tap. Then I use the red wire on that image and it runs under the console and out the firewall on the driver side to a relay (the low voltage signal).
Anyhow, let's talk CAN BUS. There are a /bunch/ of places you can tap onto CAN BUS in a car. The ODB-II port is just one of the easiest ones. My vehicle builder installed AMP steps so that is actually plugged into my ODB-II port and uses that. However, there are two taps (the red and grey cylinders on the wires in the pics). The Canm8 contactless reader is front and center with the blue/purple and white wire with the blue yellow wires coming out of it and sneaking over to the canm8 lazer snoop device back through the console to the canm8.
If you are looking under your dash you should find your ODB-II port. On my 21 F250 the shop manual notes the following: GY-OG (GREY-ORANGE) = can high and VT-OG (VIOLET-ORANGE) = CAN LOW. This will be your medium speed can bus that will carry all the signals like "door open" "high beams on" etc. Check and see if you don't have that. If you don't have anything plugged into your can bus you have a couple of options. You can undo that harness and isolate those wires and attach a contactless reader. Or you can get a ODB-II port plug with a breakout harness and attach to the can bus there (also no wire splicing). Or you can splice the wires. Whatever you are comfortable with. If you have an ODB-II port it basically has to have CAN-BUS wires, that is how virtually every diagnostic tool works, unless Ford made some significant changes.
I have the shop manual and attached the image for the "Gateway Module" connector for it. It is 1:1 exactly the same wire colors and pin out as the ODB-II port. Including port 22 and 23 in the diagram (which is the wires we were discussing above). So, as far as I can tell "Gateway Module" is Ford parlance for "ODB-II" port. At least, based on my somewhat careful reading of the shop manual. Anyway, also attaching a PDF of the gateway module wiring. See if those colors don't match what you have. If you really don't have something like all this then all bets are off. I paid like $100 for the shop manual from some third party site that compiles a shop manual based on your VIN. It seemed sketchy but it worked and I now own a 17,000 page PDF with all the shop procedures and wiring diagrams for my truck. Highly recommend that if you can swing it. It makes modding the truck a lot easier as you can pretty confidently trace wiring and such throughout the truck then. I got mine from https://www.factory-manuals.com and it took many many hours of guess work out of this process for me, even though I ended up using the ODB-II port
EDIT: I should add, I sort of cheated. The reason the blue and white wires are going into the contactless reader ais because my truck builder had already tapped the previously mentioned correct can bus high and low wires for my AMP step. And those were much easier to work the contactless reader onto without undoing the ODB-II port wiring harness. So I gave it a quick test and it worked, so I left it at that.
EDIT 2: The gateway module connector you see in the images below plugs into the backside of the ODB-II port. ODB-II port has a standard layout that obviously differs from the gateway module connector a bit. Good luck and happy wire hunting!
Yeah my odb2 port is different, white plug and the few wires that does have runs up into the main harness and disappears. No module in-between. i'll shoot a pic later today.
After some serious searching I found some info on another thread hear. Looking like my gateway module is behind the 12" sync 4 screen.
09-22-2021, 03:37 PM
