Hello,
Maybe start by checking the lamp's pins.
First, measure the wiring with a multimeter to determine which pin/wire the turn signal is on. Then, check the pins in the lamp itself (the lamp must be on the same pin). Check the lamp's operation by connecting it to a laboratory power supply. Note that the power supply isn't always LED; it's 12V, maybe 2.7V, or it's labeled on the lamp. Then, read/recode the back of the lamp and repeat the measurements with a multimeter. What diagnostic interface do you have?