Why did the letter light next to the gear shift suddenly stop working?

[Melanie]

Possible causes for the malfunctioning gear shift indicator light include: gear shift light failure, PCM (Powertrain Control Module) malfunction, transmission gear position sensor failure, damaged shift light module, short circuit or open circuit in the gear light assembly, short circuit or open circuit in the gear selector switch, or instrument panel electrical failure. Introduction to automatic transmission: 1. Gear positions: From top to bottom they are: P (Park), R (Reverse), N (Neutral), D (Drive), S (Sport), L (Low). For driving an automatic transmission vehicle, only P (Park), R (Reverse), N (Neutral), and D (Drive) are typically needed for normal driving. 2. Precautions: Do not press the accelerator pedal when shifting gears, avoid immediately pressing the accelerator pedal hard after shifting, the vehicle can only be started in P or N position, the brake pedal must be pressed to move the shift lever out of P position, and never shift into N position while driving to coast.