A school bus is equipped with ABS, and the ABS warning lamp remains on after the normal startup check. Which statement is most accurate?

1. The bus still has regular brakes, but ABS may be unavailable and should be serviced
2. The bus has no braking ability and must be stopped by shifting gears only
3. The stop arm will not work until ABS resets
4. The driver should pump the brakes at every stop to restore ABS