LR3/Disco 3
The parking brake has two warning indicators, one amber and one red, located in the speedometer of the instrument
cluster.
Amber Parking Brake Warning Indicator
The amber parking brake warning indicator is continuously illuminated if there is a parking brake system fault. Operation
of the indicator is controlled by a high speed Controller Area Network (CAN) bus signal from the parking brake module to
the instrument cluster.
Red Parking Brake Warning Indicator
When the parking brake is applied, the red parking brake warning indicator is continuously illuminated while the ignition is
on and for 3 minutes after the ignition is switched off. If the system is unable to comply with an apply or release request,
due to a system fault, the indicator flashes.
When the ignition is on and the indicator is not flashing, operation is controlled by a high speed CAN bus signal. When the
ignition is off or when the indicator is flashing, operation is controlled by a hardwired signal from the parking brake module
to the instrument cluster.
Text Messages
On vehicles with the high line instrument cluster, when there is a fault condition, illumination of the warning indicators is
accompanied by a text message displayed in the message center. For additional information, refer to
Instrument
Cluster
(413-01 Instrument Cluster)
PARKING BRAKE MODULE
The parking brake module monitors external and internal inputs and adjusts the tension of the brake cables to operate the
drum brakes and provide the required parking brake function.
The parking brake module is installed on a support bracket attached to the front of the spare wheel carrier. Two rubber
mounts, installed on lugs on the underside of the parking brake module, locate in holes in the support bracket. The top
corners of the parking brake module are secured to the support bracket with rubber mounts and flanged nuts.
The main components of the parking brake module are:
l
A Printed Circuit Board (PCB) incorporating the Application Specific Integrated Circuit (ASIC) for control of the
parking brake.
l
An electric motor.
l
A gearbox.
l
A spline shaft.
l
A force sensor.
The spline shaft and the force sensor are connected together by a latch on the end of the spline shaft. The spline shaft
rotates on the latch and moves axially in the gearbox. The latch and the force sensor slide in a channel in the body of the
parking brake module.
To apply or release the drum brakes, the parking brake module runs the electric motor, which drives the gearbox. The
gearbox turns the spline shaft to increase or decrease the tension in the brake cables. The parking brake module
monitors the load exerted by the brake cables using the input from the force sensor.
Interior of Parking Brake Module
2
Amber warning indicator (all except NAS)
3
Red warning indicator (NAS only)
4
Amber warning indicator (NAS only)
