2021 GMC Sierra LED Turn Signals Are Hyperflashing

Updated 02/23/2022 | Published 02/22/2022

Question:

My gmc keeps telling me that there is a problem with my right and left turn signal. They also rapid flash. The truck also says that there is a problem with my brake lights. My truck is a 2021 gmc Denali 3500HD DRW My camper is a 2020 DRV 44 Houston it has LED lights for everything. There is a controller of some sort for the brake and turn signal lights. The turn lights and stop lights use different led lights.

asked by: Tim C

Expert Reply:

It sounds like you have a common phenomenon known as "hyperflashing" occurring on your truck.

The reason your LED lights are flashing is because the LED lights draw such little power that your turn signal relay sees the bulbs being out. The Load Resistor Kit # DI34ZR will mitigate this issue by installing these inline with your factory wiring.

To correct your turn signals on your 2021 GMC Sierra 3500, I recommend installing the Load Resistor Kit for LED Turn Signals # DI34ZR.

expert reply by: Bryce D