Indicator Lights: Anti-Lock
LED is controlled by IPC, using information sent by Truck Body Control (TBC) module and/or Anti-lock Brake System (ABS) module on Class 2 serial data line. If light is on, brake system will still operate, but without anti-lock assistance. As a check, LED illuminates for 3 seconds after ignition is turned on.
WARNING:
If BRAKE light is on, ensure brake hydraulic system is okay before driving vehicle.