jpaytoncfd

Ok a few things to note. CANBUS has nothing to do with the load sensing. That whole thing came from Audi or BMW where there was actually a CANBUS connected sensor at each light. The only CANBUS in our trucks is between the ECM and SJB. Theres one to the Radio too if you have SYNC.

When your tail light is on there is power being drawn through the SJB. Our bulbs are 8.3W. There is only one output to each side on the rear so both bulbs are in the same circuit. The SJB uses a special IC to mesaure the drawn wattage. It only measures when your turn signal is on. The IC is very simple. If the wattage is below its threshold it outputs on one of its pins. The IC that controlls the Flash rate "watches" that pin to know is there is a bulb out. Now the Wattage sensing IC's threshhold is set by a resister between two pins. By changing the resistance you can change the threshold. You could even place a adjustable resistor (potentiometer) and be able to adjust the threshold on the fly. So our trucks currently look for a load of 16.6 in the rear. Good LED's are going to be around 1-2 watts. Mine are 2.3. So the threshold is likely around 15w. There would be a large buffer for differences in bulbs and conditions that would affect the current draw. I would not be surprised if it was set at 9-10 watts. Just above what one bulb draws. I would adjust it to look for 2.5W That way if one bulb goes it WILL still hyperflash.

And if your wondering why I would not just use load resistors. I do. They are very unreliable. Thier draw changes in different temperatures. They get very hot making a fire hazzard. and they dont allow me any notification of a blown bulb. The reason I want to get a broken SJB is so I can view and test my theory before trying it on my own truck. But I would still rather risk the $200 SJB then the whole $50,000 truck if some gas spills from a gas can and makes its way to the resistors and flashes.

To sum this all up. There are two ways to prevent hyperflash in our trucks when using LEDs.
1. waste extra electricity as heat to "trick" the SJB into thinking there is a proper bulb there.
2. Modify the SJB to work as it should with LEDs.

The CANBUS bulbs, Load resistors, and prebuilt decoders are all the same thing. They use 1-2 watts for the LEDs and 10+ watts for tiny heaters.

jpaytoncfd

FYI, http://en.wikipedia.org/wiki/CAN_bus

jpaytoncfd

Not exactly. The SJB includes the circuit that used to be in the external flashers. (the electronic ones). They basically just built the same flasher into the SJB.

johnday in BFE

iTrader: (1)

Excellent explanation, thank you. If I ever have a spare SJB, I'll send it to ya!LOL

RLXXI

@jpaytoncfd


Apparently you are explaining an older system, my 2013 does not use a SJB, (smart junction box)? I'm guessing that's what you mean, never heard of it, everything for turn, stop, hazard runs thru the BCM (body control module) and even if it had an SJB would that not be a processor of information? I think it would qualify making my statement about the flasher being controlled by computer accurate, just saying.

When I left the dealer in 04 we were just getting into CAN controller area networks but I have a good grasp of how they operate, or did back then, I'm sure it's changed by now.

Evidently Ford has rolling changes due to technological advances coming faster and faster with every advancement.

Boggles the mind to think how our vehicles systems will be controlled in just 10 years comparing today's with only 10 years ago.


I have the option for lights out warning on my truck, I just verified it a few mins ago with IDS, it's in Module programming> programmable parameters> exterior lighting. Same place to activate day time running lights, yeah I own my own Bosch VCMII/IDS currently running v91.05







As I stated before I have the CANBUS compatible led's in my front turn lamps, they do not hyper flash with lights off, only with lights on and I'm not so sure a load resistor or that other device posted about will work with current technology. Best guess is the difference front to rear with the rear turn lamps being original non led, I will test that theory as soon as I get some rear led's.



.

dosman

2013 and F-150s, of course; model: Platinum.

superbrightleds resistors shipped with the needed scotch locks.

johnday in BFE

iTrader: (1)

As I stated before I have the CANBUS compatible led's in my front turn lamps, they do not hyper flash with lights off, only with lights on and I'm not so sure a load resistor or that other device posted about will work with current technology. Best guess is the difference front to rear with the rear turn lamps being original non led, I will test that theory as soon as I get some rear led's.



.[/QUOTE]


That's what I was going to do, glad I waited for you to say it.LOL
I guess I'll just go ahead and get the CAN compatible ones, and see what happens next week. But it would be interesting to figure out why your front ones are acting like that.

Thislilfishy

It could be the load resistor is only on the flasher side lead of the LED, perhaps if it was moved to the ground side? Maybe the system is hyper flashing as it sees the marker light as being burned out.


Ian

RLXXI

All turn lamps, front and rear flash normal until I turn on the light switch to either parking only or park/head. Then they all go hyper including the lights in the side view mirrors.


I have the led CB up front but old fashioned 3057 out back, I have 4 of the red CB led's coming for the rear turn lamps.


I'm hoping when the body control module see's equal current draw all the way around it will act normal, expensive experiment but it's only $$ right? LOL


.

johnday in BFE

iTrader: (1)

You just used regular, non Can bus, LEDs?