2020 1500, No rear lights AT ALL!

[philodog]

UPDATE: Fixed. Somehow BOTH wiring connectors to the taillight assemblies were disconnected. I don't know how this is possible since they have those annoying lock tabs that are difficult to release and I have never touched them before. My only thought is that they were not completely connected at the factory and it took a few years of vibration for them to come loose. Unfortunately the Service Stop/Start System light is still on. so still have to investigate that. Thanks for the answers.

Searched but didn't find this issue. All of a sudden I have no rear lights whatsoever. No running, brake,reverse,turn signal lights. Also the "Service Stop/Start System" light came on. All fuses are good. Haven't checked bulbs yet but I can't imagine all went out at once. Front running and turn signals work. I am stumped. Any ideas? For what it's worth the truck just had the TSB software update which makes me suspicious. Thanks.

 

[Redz72]

How old is your battery? Often times, an old, weak battery causes all sorts of crazy problems. No rhyme or reason either.

 

[kapinallinen2]

Searched but didn't find this issue. All of a sudden I have no rear lights whatsoever. No running, brake,reverse,turn signal lights. Also the "Service Stop/Start System" light came on. All fuses are good. Haven't checked bulbs yet but I can't imagine all went out at once. Front running and turn signals work. I am stumped. Any ideas? For what it's worth the truck just had the TSB software update which makes me suspicious. Thanks.

A blown fuse or a single bad ground should not cause all of the rear lights to go out at the same time?
I suppose it is possible.

One of the things common with all the lights is the BCM.
Did the TSB update corrupt it? perhaps.
RF hub got wet and messing with the Can-bus, a possibility.
As mentioned, a failing battery can cause havoc with the modules.

Back to the BCM:

“5. Ineffective BCM inputs or outputs.

5. Use a diagnostic scan tool to test the BCM inputs and outputs. Refer to the appropriate diagnostic information.”

You pull any codes?

 

[theblet]

Check for water or moisture in your tail lights

 

[Cbty2050]

Check the online connectors at the lr corner of the truck. They like to corroded