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In case you're not sure if you have BLIS, the lights that include BLIS radar look like this. Lower portion is darker, doesn't light up, and has the radar symbol.
Appreciate it...yes it has BLIS. Mine is the one on the right.
Coincidentally, Ford / OEM auto part stores want at least $1,000 for the tail light.....it's just plastic and doesn't even have the radar. I'm baffled as to how they can get away with that or why they even charge $1,000 in the first place. That's why I've put off replacing my left tail light for 2 years. Found one on Ebay that hopefully works out for $200...supposedly OEM.
It does have BLIS. Apologies, what is the CAN network?
I did disconnect the left tail light this weekend and reconnected but didn't seem to help anything.
CAN (controller area network) is how different modules in more modern vehicles communicate. Basically, instead of running an individual wire for everything, you have a twisted pair of 2 wires that is shared by various modules. They can talk to each other digitally over that 2 wire network.
In our trucks there are actually a few separate CAN networks. I believe there are 3: high speed, medium speed, and low speed. High speed is for the high importance things, medium and low are for less critical stuff.
Since all the modules on a given network share those 2 wires, a short between those 2 wires at any point knocks out communication to everything in the chain.
So, if the CAN lines to the BLIS radar are shorted anything else that shares that CAN network will be down. I can't say if that's what's happening here, but it's the type of thing that could drive you nuts trying to diagnose if you don't know about it, so I wanted to bring it up. It might be worth leaving the BLIS sensor unplugged, then disconnecting and reconnecting the battery to let everything boot up fresh. See if the truck is happy. I'm guessing you should get a code for a missing BLIS sensor. Assuming there's not corrosion causing a short in the connector that should tell you if it's shorting the CAN.
As for the price of the BLIS taillights... It seems they have become somewhat of a desirable status symbol of sorts. People are modding in BLIS lights without sensors for the aesthetics. To each their own ¯\_(ツ)_/¯
CAN (controller area network) is how different modules in more modern vehicles communicate. Basically, instead of running an individual wire for everything, you have a twisted pair of 2 wires that is shared by various modules. They can talk to each other digitally over that 2 wire network.
In our trucks there are actually a few separate CAN networks. I believe there are 3: high speed, medium speed, and low speed. High speed is for the high importance things, medium and low are for less critical stuff.
Since all the modules on a given network share those 2 wires, a short between those 2 wires at any point knocks out communication to everything in the chain.
So, if the CAN lines to the BLIS radar are shorted anything else that shares that CAN network will be down. I can't say if that's what's happening here, but it's the type of thing that could drive you nuts trying to diagnose if you don't know about it, so I wanted to bring it up. It might be worth leaving the BLIS sensor unplugged, then disconnecting and reconnecting the battery to let everything boot up fresh. See if the truck is happy. I'm guessing you should get a code for a missing BLIS sensor. Assuming there's not corrosion causing a short in the connector that should tell you if it's shorting the CAN.
Good luck!
Appreciate the help! Will try that tonight as well.
I would also check the connectors/wiring located on top of the driver-side front wheel well cover (under the hood, next to brake booster)(3 or 4 od them).
Checked the wiring under the hood....mouse got in there and chewed apart a handful of wires.
That is unfortunate, but at least you've located the issue. If it's just a few it should be a pretty straightforward fix. Best of luck with the repair!
If it turns out to be more extensive it might be worth checking if rodent damage is covered under your insurance.
