A red ABS warning light has no different meaning from an orange or yellow warning light.
The warninght light can turn on for a few reasons:
- One or more wheel speed sensors have failed
- One or more wheel speed sensors are covered with road grime
- One or more wheel speed sensors are unreachable (broken wire)
- A blown fuse for the system
- The ABS module is not working
When the brake fluid level is low, this will not throw an ABS warning light, but a brake warning light instead.