Flashing trailer lights

[insidethreat07]

I have a 2020 Silverado 2500 HD LTZ and when my car trailer is plugged into the truck while the truck is turned off, the led brake lights on the trailer will very dimly flash once every 3-5 seconds. Not sure if the security light is back feeding through the trailer lights? There is no issues while the truck is running, only while it id turned off. Any ideas?

 

[Limelight]

8 minutes ago, insidethreat07 said:

I have a 2020 Silverado 2500 HD LTZ and when my car trailer is plugged into the truck while the truck is turned off, the led brake lights on the trailer will very dimly flash once every 3-5 seconds. Not sure if the security light is back feeding through the trailer lights? There is no issues while the truck is running, only while it id turned off. Any ideas?

 

It’s normal. That’s how the trailer detection system works.  

[insidethreat07]

Just now, Limelight said:

It’s normal. That’s how the trailer detection system works.  

Thanks. I just seen other threads on it after I posted of course lol

[KC Desert]

I noticed this at 2 AM while camping and promptly unplugged that stupid thing. 

[bass mechanic]

On 4/27/2020 at 9:45 PM, KC Desert said:

I noticed this at 2 AM while camping and promptly unplugged that stupid thing. 

that stupid thing is part of the alarm that when unplugged will set off the alarm letting you know someone stole your trailer.

[Orville Boger]

How do you turn it off?

[Another JR]

There is a modification you can do to the trailer light circuit (I believe it’s the marker light circuit that is used for trailer presence detection) that will stop the LED lights from flashing without defeating trailer detection. The mod changes the circuit resistance, but I can’t remember the details. You should be able to find it with a search. 

[ambest]

There is a control module under the truck. if you take it to your dealer they have an updated module that is used on a 2021 that will correct the problem. They should do it under warranty.