LR3/Disco 3
DSC Warning Indicator
The DSC warning indicator is an amber colored warning indicator located in the tachometer.
Each time the DSC or the ETC function is active, the DSC warning indicator flashes at 2 Hz. If DSC has been selected off,
or there is a fault that disables the DSC or the ETC function, the DSC warning indicator is continuously illuminated. If DSC
has been selected off, vehicles with the high line instrument cluster also display a message, advising that DSC is
switched off. For additional information, refer to
Instrument Cluster
(413-01 Instrument Cluster)
Operation of the DSC warning indicator is controlled by a high speed CAN bus message from the ABS module to the
instrument cluster.
When the ignition switch is first turned to position II, the DSC warning indicator illuminates for approximately 3 seconds as
a bulb check. If a fault during the previous ignition cycle caused the DSC warning indicator to be illuminated, the DSC
warning indicator may remain illuminated after the next bulb check, even if the fault has been rectified and cleared from
the ABS module; the DSC warning indicator may remain illuminated during vehicle operation while additional checks of
the related inputs are performed.
HDC Information Indicator
The HDC information indicator is a green colored indicator located in the tachometer.
The HDC information indicator is continuously illuminated while the HDC function is selected on and the vehicle is within
the parameters for HDC operation; when the vehicle is outside the parameters for HDC operation, the HDC information
indicator is flashed at 2 Hz.
Operation of the HDC information indicator is controlled by a high speed CAN bus message from the ABS module to the
instrument cluster.
HDC Warning Indicator
On the low line instrument cluster, the HDC warning indicator is an amber colored indicator located between the
tachometer and the speedometer. On vehicles with the high line instrument cluster, the HDC warning indicator consists of
a message in the message center.
On the low line instrument cluster the HDC warning indicator is continuously illuminated if there is a fault that affects the
HDC function, and flashed at 2 Hz if the HDC function is temporarily unavailable because of brake overheat.
On the high line instrument cluster, appropriate messages are displayed in the message center if there is a fault that
affects the HDC function, or if the HDC function is temporarily unavailable because of brake overheat. For additional
information, refer to
Instrument Cluster
(413-01 Instrument Cluster)
Operation of the HDC warning indicator is controlled by a high speed CAN bus message from the ABS module to the
instrument cluster.
On the low line instrument cluster, when the ignition switch is first turned to position II, the HDC warning indicator
illuminates for approximately 3 seconds as a bulb check.
HCU
The HCU is a 4 channel unit that modulates the supply of hydraulic pressure to the brakes under the control of the ABS
module.
The HCU is attached by three mounting bushes to a bracket in the plenum box on the driver side of the engine
compartment. Hydraulic pipes connect the HCU to the master cylinder and the brakes. For additional information, refer to
Hydraulic Brake Actuation
(206-06 Hydraulic Brake Actuation)
The primary and secondary outlets of the master cylinder are connected to primary and secondary circuits within the
HCU. The primary circuit in the HCU has separate outlet ports to the front brakes. The secondary circuit in the HCU has
