Grand Cherokee 2WD V8-4.7L VIN J (2004)
ABS Light: Description and Operation
ABS and Red Brake Warning Indica
ABS AND RED BRAKE WARNING INDICATOR
The amber ABS warning indicator is located in the instrument cluster. It is used to inform the driver that the antilock function has been turned off due
to a system malfunction. On the WJ, the CAB controls the lamp indirectly.
The CAB monitors its own functions. If the CAB determines that the ABS indicator should be on, the CAB sends a message via the PCI BUS to the
instrument cluster and the cluster turns on the indicator.
The instrument cluster sends a message over the PCI BUS at regular intervals, if the CAB does not respond the instrument cluster will illuminate the
ABS indicator.
The red brake warning indicator is located in the instrument cluster. It can be activated by application of the parking brake, a leak in the front or rear
wheel brake hydraulic circuit which causes the master cylinder reservoir to be low on fluid, or by turning the ignition switch to the start position. The
red brake warning indicator can also be turned on if the brake fluid level switch circuit becomes open or shorted to ground.
