Land Rover Anti Lock Control Traction Control Rover Manual

							•The battery is disconnected or battery voltage
decreases below 7.5 volts while the parking brake is
applied, so that the parking brake cannot be
electrically released.
The parking brake is mechanically released by
disconnecting the force sensor from the spline shaft in
the parking brake module. During normal operation, the
force sensor and the spline shaft are locked together by
a lever operated pawl on the end of the spline shaft,
which engages with a spigot on the force sensor.
The emergency release cable is a Bowden cable installed
between the parking brake module and the center
console. The emergency release cable is held in clips
along the underside of the vehicle and enters the
passenger compartment below the center console
through an aperture in the transmission tunnel. A quick
release fitting seals the emergency release cable in the
aperture. At the parking brake module, a sealing collar
on the outer cable is a push fit in the housing of the
parking brake module.
In the center console, a pull ring is installed on the end
of the inner cable. The pull ring is designed to fit the
hook on the end of the jack handle which, in
combination with a screwdriver shaft, can be used to
pull on the cable.
The pull required to release the latch is approximately
200 N (45 lbf). When the pull ring of the emergency
release cable is released, the spring in the parking brake
module retracts the inner cable and the nipple moves
away from the pawl operating lever.
After the emergency release cable has been used to
release the parking brake, the next time an apply
selection is made with the parking brake switch, the
parking brake module automatically runs through a
latching procedure to reconnect the spline shaft with
the force sensor. The parking brake module turns the
spline shaft so that it moves towards the force sensor.
The pawl of the spline shaft then re-engages with the
spigot of the force sensor. A second apply selection with
the parking brake switch is required to apply the parking
brake.
CLUTCH PEDAL POSITION SENSOR
(MANUAL TRANSMISSION MODELS
ONLY)
Clutch master cylinder1
Electrical connector2
Clutch pedal position sensor3
The clutch pedal position sensor supplies a signal of
clutch pedal position to the parking brake module.
The clutch pedal position sensor is a Hall effect sensor
which is attached to the side of the clutch master
cylinder. The position of the piston in the clutch master
cylinder effects a magnetic field in the sensor, and is
translated by the sensor into an analogue voltage signal
for the parking brake module. The parking brake module
relates the signal to the position of the clutch pedal.
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							PARKING BRAKE INDICATORS
Red warning indicator (all except NAS)1
Amber warning indicator (all except NAS)2
Red warning indicator (NAS only)3
Amber warning indicator (NAS only)4
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.
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:
•A Printed Circuit Board (PCB) incorporating the
Application Specific Integrated Circuit (ASIC) for
control of the parking brake.
•An electric motor.
•A gearbox.
•A spline shaft.
•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.
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							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
Electrical connector1
Housing2
Electric motor3
PCB4
Spline shaft5
Gearbox6
Force sensor7
Inputs and Outputs
A 32 pin electrical connector on the RH side of the
parking brake module provides the interface between
the PCB and the vehicle wiring.
The parking brake module is powered by two permanent
battery power feeds from the Battery Junction Box
(BJB). Two connections with the Central Junction Box
(CJB) provide battery voltage signals when the key is
in the ignition switch (key in) and when the ignition
switch is in position II (ignition). Other hardwired inputs
consist of those from the parking brake switch and, on
manual transmission models, the clutch pedal position
sensor.
In addition to the hardwired connections, the parking
brake module is connected to the high speed CAN bus
to enable communication with other vehicle systems.
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							Parking Brake Module Harness Connector C2178
Parking Brake Module Harness Connector C2178 Pin Details
Input/OutputDescriptionPin No.
-Not usedA1
Input/OutputHigh speed CAN bus low outA2
Input/OutputHigh speed CAN bus high inA3
Input/OutputHigh speed CAN bus low inA4
-Not usedB1
Input/OutputHigh speed CAN bus high outB2
InputParking brake switch SW1B3
InputParking brake switch SW4B4
-Not usedC1 and C2
InputParking brake switch SW2C3
OutputParking brake switch SW5C4
-Not usedD1 to E1
InputClutch pedal position sensor groundE2
InputClutch pedal position sensor signalE3
OutputClutch pedal position sensor power supplyE4
-Not usedF1
InputKey in ignition switchF2
InputIgnition power supplyF3
OutputRed parking brake indicatorF4
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							Input/OutputDescriptionPin No.
-Not usedG4
OutputGroundG2
-Not usedG3
InputBattery power supplyG4
-Not usedH1
OutputGroundH2
-Not usedH3
InputBattery power supplyH4
PARKING BRAKE OPERATION
The parking brake can be applied at any time provided
sufficient battery power is available. For the parking
brake to be released, various pre-conditions are required.
The parking brake has manual and automatic operating
modes, to cater for different operating circumstances,
as detailed in the following table:
Operating Modes
Driver ActionPre-ConditionsMode
Pull up parking brake
switch.
Vehicle speed less than 2.5 km/h (1.6 mph).Static apply
Press down parking brake
switch.
1. Vehicle speed less than 2.5 km/h (1.6 mph).
2. Engine running.
OR
Ignition switch in position II and brake pedal or clutch
pedal pressed (manual transmission).
OR
Ignition switch in position II and brake pedal or accelerator
pedal pressed (automatic transmission).
Static release
Remove key from igni-
tion switch.
1. Vehicle speed less than 10 km/h (6.25 mph).
2. Ignition switch in position 0.
3. Key in ignition switch.
Key out apply
Remove key from igni-
tion switch while
pressing down parking
brake switch.
1. Vehicle speed less than 2.5 km/h (1.6 mph).
2. Ignition switch in position 0.
3. Key in ignition switch.
Key out apply inhibit
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							Driver ActionPre-ConditionsMode
Pull up parking brake
switch as required.
Vehicle speed more than 2.5 km/h (1.6 mph).Dynamic apply
Release (to neutral posi-
tion) or press down
parking brake switch.
Vehicle speed more than 2.5 km/h (1.6 mph).Dynamic release
None. Parking brake
released automatically on
drive away.
1. Ignition switch in position II.
2. Transmission in gear 1, 2 or R (with high range selected)
or 1, 2, 3 or R (with low range selected).
3. Accelerator pedal pressed more than 5%.
DAR (automatic transmis-
sion only)
Operating Voltages
Actuation of the parking brake (apply or release) is only
started if the power supply to the parking brake module
is within 9 to 18 volts. At any voltage in this range, the
parking brake module is able to tighten the brake cables
to the maximum, to fully apply the parking brake,
although at voltages between 9 and 10.5 volts the
actuation time may exceed 1.0 second.
During a parking brake actuation:
•If the power supply to the parking brake module
decreases to less than 8.3 volts, the parking brake
module continues the actuation, but stores a related
fault code. If the ignition is on, the parking brake
module also signals the instrument cluster to
illuminate the amber parking brake warning indicator
and flash the red parking brake warning indicator.
On vehicles with the high line instrument cluster, a
message advising there is a parking brake fault is
shown in the message center. The warning
indications are discontinued if the power supply
voltage increases to 8.3 volts or more.
•If the power supply voltage decreases to less than
7.5 volts, the parking brake module discontinues the
actuation. Actuation is automatically resumed if the
power supply voltage subsequently increases to 7.5
volts or more and the parking brake switch request
is still valid.
•If the power supply voltage decreases below 6.5
volts, the parking brake function is disabled for the
remainder of the ignition cycle.
•If the power supply voltage increases to more than
18.0 volts, the parking brake module immediately
disables the parking brake function and stores a
related fault code. If the ignition is on, the parking
brake module also signals the instrument cluster to
illuminate the amber parking brake warning indicator
and flash the red parking brake warning indicator.
On vehicles with the high line instrument cluster, a
message advising that the parking brake has a fault
and is not functioning is shown in the message
center. The parking brake function remains disabled
until the power supply voltage is within 9 to 18 volts
again. When the power supply voltage is within 9 to
18 volts again, the warning indications are cancelled
and actuation is automatically resumed if the parking
brake module is in a dynamic mode of operation with
a valid parking brake switch request.
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							NOTE: The instrument cluster shuts down below 8
volts, so warning indications and messages are not
displayed below 8 volts. CAN transmission stops if
battery voltage drops below 7.0 volts and re-starts when
voltage goes above 7.5 volts.
Sleep Mode
To reduce quiescent drain on the vehicle battery, the
parking brake module incorporates a sleep mode. The
parking brake module enters the sleep mode, provided
the ignition is off and there are no signals from the wheel
speed sensors, when one of the following occurs:
•20 minutes elapse after the last actuation of the
parking brake.
•If no actuation occurred, 20 minutes elapse after the
ignition is switched off.
The parking brake module wakes up from the sleep
mode when on of the following occurs:
•An apply or release request is made with the parking
brake switch.
•The ignition is turned on.
•A key out apply is activated.
The parking brake module wakes up within 500 ms.
The high speed CAN bus is activated within 200 ms
maximum.
When the parking brake module is woken with a release
request from the parking brake switch, the parking brake
module ignores the request but illuminates the red brake
warning indicator. The parking brake module
extinguishes the red brake warning indicator and goes
back to sleep immediately the switch is released to the
neutral position.
When the parking brake module is woken with an apply
request from the parking brake switch, if the parking
brake is already applied the parking brake module
ignores the request but illuminates the red brake warning
indicator. The parking brake module extinguishes the
red brake warning indicator and goes back to sleep
immediately the switch is released to the neutral
position. If the parking brake is in the released condition
when the apply request is made, the parking brake
module illuminates the red brake warning indicator and
applies the parking brake. The parking brake module
extinguishes the red brake warning indicator and goes
back to sleep 3 minutes after the apply activation, or
immediately after the switch is released to the neutral
position, whichever occurs last.
Dynamic Apply
In the dynamic apply mode, if the vehicle speed is more
than 10 km/h (6.25 mph) when the parking brake switch
is selected to apply, the parking brake module requests
the ABS module to activate the disc brakes on all four
wheels. When the vehicle comes to a standstill, the
parking brake module statically applies the parking
brake. Once the static load is achieved, the hydraulic
pressure is removed. If the parking brake switch is
released to the neutral position, or pressed down to the
release position, during dynamic apply, braking is
cancelled.
The ABS module monitors the deceleration rate using
the wheel speed sensor signals, and adjusts the hydraulic
pressure to the disc brakes as required to achieve the
required rate. All of the anti-lock control - traction
control system brake functions remain enabled in the
dynamic apply mode.
The parking brake module incorporates two fallback
functions for the dynamic apply mode.
•Fallback 1 is invoked if vehicle speed is between 2.5
km/h (1.25 mph) and Vmax when the parking brake
switch is selected to apply and the ABS module is
unable to fulfil a hydraulic request. When fallback
1 is invoked, the parking brake module decelerates
the vehicle, using only the parking brake. The
parking brake module monitors the deceleration rate
using the wheel speed information from the ABS
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							module, and adjusts the tension of the brake cables
to achieve the required rate. During deceleration the
parking brake module also uses the wheel speed
inputs from the ABS module to operate an anti-lock
function for the rear wheels. When vehicle speed
decreases to 2.5 km/h (1.25 mph) the parking brake
module static applies the parking brake.
•Fallback 2 is invoked if there is a loss of
communication between the parking brake module
and the ABS module or the CAN bus has failed.
When fallback 2 is invoked, the parking brake
module decelerates the vehicle using only the parking
brake. The parking brake module tightens the brake
cables under the control of the driver, no anti-lock
function is available.
While dynamic apply is active, including fallback 1 and
fallback 2, the parking brake module also outputs high
speed CAN bus signals to:
•The ABS module, to apply the stoplamps.
•The instrument cluster, to sound an intermittent
warning buzzer, at 0.5 second on, 1.0 second off.
•The instrument cluster, to illuminate the red parking
brake warning indicator. The indicator is
permanently illuminated except in fallback 2, when
it flashes.
DAR Pre-arming
The DAR pre-arming function operates when the
transfer box is in high range to reduce the parking brake
release time during DAR and to provide a smooth
take-off. DAR pre-arming is invoked when:
•The ignition switch is in position II.
•The transmission is in gear 1, 2 or R.
•The vehicle is stationary.
•No failsafe tighten actuation has occurred.
Automatic Load Adjustment
While the ignition is on, the parking brake module
constantly monitors the input from the force sensor. If
the tension of the brake cables goes outside the limits
for a given operating mode, the parking brake module
automatically restores the tension within limits.
Failsafe Tighten.  If, during pre-arming, the vehicle
moves, then the maximum cable force is reinstated for
the remainder of that ignition cycle.
Automatic Apply.  While the parking brake is applied,
if the tension of the brake cables decreases by a
prescribed amount from the initial setting, the parking
brake module automatically restores the tension to the
initial setting.
Automatic Release.  While the parking brake is
released, if the tension of the brake cables increase to a
prescribed amount, the parking brake module
automatically reduces the tension to zero.
Parking Brake Switch Monitoring
The parking brake module monitors for the following
types of fault in the parking brake switch system. If a
fault is detected, the parking brake module stores a
related fault code:
•Short circuits between a pull-down transistor in the
parking brake module and battery voltage.
•Broken wires and microswitches.
•Plausibility.
The parking brake switch has a degree of in-built
redundancy. If a single microswitch fault is detected the
parking brake module can still determine the operating
state of the parking brake switch. Short circuits or
multiple failures cause the parking brake module to
disable the parking brake switch for the remainder of
the ignition cycle. The parking brake module also
disables the parking brake switch if a plausibility fault
occurs. However, since plausibility faults are usually
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							caused by incomplete operation of the parking brake
switch, the parking brake switch is re-enabled if the
parking brake module subsequently establishes a
plausible operating state.
If a single microswitch fault is detected, the parking
brake module signals the instrument cluster to illuminate
the amber parking brake warning indicator. On vehicles
with the high line instrument cluster, the parking brake
module also signals the instrument cluster to display a
message advising there is a parking brake fault. During
an apply actuation, the parking brake module also
signals the instrument cluster to flash the red parking
brake warning indicator.
For all other fault types, the parking brake module
signals the instrument cluster to illuminate the amber
parking brake warning indicator, and, on vehicles with
the high line instrument cluster, to display a message
advising the parking brake has a fault and is not
functioning. If it makes an apply actuation, the parking
brake module signals the instrument cluster to flash the
red parking brake warning indicator for the remainder
of the ignition cycle.
On the next ignition cycle, the warning indicators and
the messages are only activated if the fault is still
present, although the fault code is retained by the
parking brake module until cleared by T4.
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							PARKING BRAKE CONTROL DIAGRAM
NOTE: A = Hardwired connection; D = High speed CAN bus; N = Medium speed CAN bus
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