ABS and Red Brake Warning Indicators (EBC 125 and EBC 325)

ABS WARNING INDICATOR AND RED BRAKE WARNING INDICATOR (EBC 125 AND EBC 325)
The system is equipped with amber ABS and a red Brake warning indicator to alert the driver of a malfunction it has detected. The CAB can signal the operation of both the amber ABS warning indicator and the red Brake warning indicator via PCI Bus. The CAB controls the ABS warning indicator by making it do one of three things:
^ Light steady for 3.4 seconds during an initial test at the beginning of an ignition cycle to function as a bulb check.
^ Light steady when a system malfunction exists.
^ Flash if a vehicle tooth or tire parameter is faulty or missing.

The Instrument Cluster controls the amber Antilock Brake system-warning indicator. All Dodge Truck Instrument Clusters have direct control over the ABS warning indicator and Brake warning indicator. The Instrument Cluster transmits a message over the PCI BUS relating to diagnostics and current lamp status for the ABS and Brake indicator. The Instrument Cluster will expect a PCI BUS message back from the CAB indicating whether the indicator should be illuminated on or off. In the event that no signal is received from the CAB for a certain amount of time, the Instrument Cluster will illuminate the ABS warning indicator. The indicator provides notice of ABS system-related problems and the need to take diagnostic action.

The vehicle Instrument Cluster has a red Brake warning indicator to alert the driver to the following conditions:
^ Brake fluid level low
^ Parking Brake applied
^ ABS system malfunction

The Instrument Cluster controls the red Brake warning indicator. There is a parallel path to chassis ground that will illuminate the red Brake warning indicator:
^ Through the parking Brake switch contacts
^ Through the Brake fluid level switch
^ Through the CAB via PCI BUS

The CAB can control the operation of both the amber ABS warning indicator and the red Brake warning indicator:
^ If the CAB is disconnected, the amber ABS warning indicator and red Brake warning indicator will be illuminated
^ If the axle type or tire size are not programmed properly, the amber indicator will blink
^ If any Foundation Brake system problem exists
^ If any ABS system DTC is set, both the amber and red indicators will be illuminated