Do I need to replace the brake disc and pads when the Audi A6L brake warning light comes on?

Q: The Audi A6L has traveled 80,000km and the brake warning light comes on. After checking at the 4S shop, I need to replace the brake disc and pads. Is it necessary?
A: The front and rear wheel brakes of the Audi A8L are both ventilated discs, and their replacement has a standard. If there is a slight sound of “iron rubbing against iron” or a clamoring sound when you lightly brake, the brake pads must be replaced immediately. Because the limit marks on both sides of the brake pads have directly rubbed against the brake disc, it proves that the wear of the brake pads has exceeded the limit. Most brake disc products have wear indicators, and there will be 3 small pits on the disc surface. Use a vernier caliper to measure the depth of the small pits, which is 1.5mm. If the total wear depth of both sides of the brake disc reaches 3mm, the brake disc should be replaced in time.