Land Rover Body And Paint Air Bag And Safety Belt Rover Manual

							•Control and monitoring of the switch status LED
and lead
•Evaluation and monitoring of the control inputs
•Management of diagnostic and test functions
•Monitoring of power supply
•Communication via diagnostic link.
Parking Aid connector Pin Details
Connector C0957A
Connector C1457 (Front sensors only)B
Connector C0958 (Rear sensors only)C
Connector C0957
Input/OutputDescriptionPin No.
InputIgnition supply1
OutputRear sounder2
-Not used3
InputSwitch (ground)4
-Not used5 and 6
Input/OutputCAN low7
-Not used8 and 9
InputRear sounder 12V supply10
-Not used11 and 12
OutputSwitch LED13
Parking AidLesson 2 – Electrical
111Technical Training (G421252) 
						

							Input/OutputDescriptionPin No.
Input/OutputCAN high14
-Not used15
InputGround16
Connector C01457
Input/OutputDescriptionPin No.
InputGround - Front sensors1
Output12V power supply - front sensors2
-Not used3 and 4
InputSensor signal - front left outer5
InputSensor signal - front left inner6
InputSensor signal - front inner right7
InputSensor signal - front outer right8
-Not used9 to 12
Connector C0958
Input/OutputDescriptionPin No.
-Not used1
InputSensor signal - rear inner right2
InputSensor signal - rear inner left3
InputSensor signal - rear outer right4
InputSensor signal - rear outer left5
-Not used6 and 7
InputGround - rear sensors8
-Not used9 and 10
Output12V power supply - rear sensors11
-Not used12
(G421252) Technical Training112
Lesson 2 – ElectricalParking Aid 
						

							Inputs and Outputs
Three connectors on vehicles with front and rear sensors
and two connectors on vehicles with rear sensors only
provide the interface between the parking aid module
and the external parking aid components.
The module receives inputs from the following:
•Reverse selected - CAN message from transmission
control module (automatic transmission) or transfer
box control module (manual transmission)
•Forward gear selected (not in reverse or neutral) -
CAN message from transmission control module
(automatic transmission) or transfer box control
module (manual transmission)
•Parking aid switch
•Parking brake applied - CAN message
•Trailer fitted - CAN message for central junction
box
•Ignition switch - Power supply
The module outputs signals to the following:
•Sensors - power and ground connections
•Sensors - digital signal - transmit and receive signals
•Rear sounder - varying frequency output
•Front sounder - CAN message to instrument cluster
•Parking aid switch - power supply for switch LED
operation
Controller Area Network (CAN) Signals
The parking aid module sends and receives a number
of digital signals via the medium speed CAN. The
received signals are used for operation of the parking
aid system. On vehicles with a high specification
entertainment and information system, the transmitted
signals, which represent distance to obstacle calculations
from the sensors, are received by the integrated head
unit and are used to display parking aid information on
the touch screen display.
The parking aid module receives the messages shown
in the following table which are used to control the
parking aid system.
Transmitted byMessage
ABS moduleVehicle speed
Transmission control
module
Selected gear position -
Automatic transmission
Transfer case control
module
Selected gear position -
Manual transmission
Electric park brake
module
Electric park brake on/off
ABS moduleVehicle movement status
Central junction boxTrailer connected
HEVAC moduleAmbient temperature
Diesel engine control
module
Engine running status
Instrument clusterStored odometer reading
Instrument clusterVehicle voltage level
Instrument clusterMinute counter
Instrument clusterCar configuration
T4 via diagnostic
socket
Diagnostic physical request
T4 via diagnostic
socket
Diagnostic functional
request
Instrument clusterMaster configuration identi-
fication
Diagnostics
The parking aid module has a diagnostic connection via
the medium speed CAN to enable faults to be retrieved
using T4. Additionally, an on-board diagnostic routine
Parking AidLesson 2 – Electrical
113Technical Training (G421252) 
						

							within the parking aid module constantly monitors the
system and alerts the driver to a system fault by emitting
a tone from the front or rear sounder, depending on the
fault.
If a parking aid system fault has occurred, the parking
aid module will relay the occurrence of the fault to the
driver in the following ways:
•The status LED will flash at a frequency of 2Hz if
the system is active and fault is detected in the
sensors, sounders, related wiring or the module.
•The front sounder will emit an error tone for 3
seconds at a frequency of 1500Hz if a fault is
detected with the front sensors or the rear sounder
develops a fault.
•The rear sounder will emit an error tone for 3 seconds
at a frequency of 1500Hz if a fault is detected with
the rear sensors, the switch, the LED in the switch
or if there is a CAN bus error.
SENSORS
Front sensor housing1
Front sensor2
Rear sensor housing3
Rear sensor4
Four sensors are positioned in the rear bumper and the
front bumper (if fitted). Each sensor housing has two
raised location keys which locate in corresponding
grooves in the bumper mounting hole and sets the
correct orientation for the sensor bodies. The housings
are clipped into the bumper from the front. The sensors
are then clipped into the housings from the rear.
Each sensor has a three pin connector which connects
into a common harness linking all four sensors. This
harness is connected to the main vehicle body harness
for the rear sensors or the engine compartment harness
for the front sensors. The three pins are for sensor
negative and positive feeds and a signal line.
Each sensor comprises a plastic housing which contains
a piezoelectric disc. The disc resonates at a frequency
of 38.4 kHz, producing an ultrasonic signal output. The
disc also receives the reflected echo signal.
The parking aid module controls the operating mode of
each sensor by the output of a digital signal on the signal
line. Each sensor has two modes of operation; combined
transmitter and receiver mode or receiver mode only.
In the combined mode, the sensor emits a series of
ultrasonic impulses and then switches to receiver mode
to receive the echo reflected by an obstacle in the
detection range. These echo signals are amplified and
converted from an analogue signal to a digital signal by
the sensor. The digital signal is then transmitted to the
parking aid module and compared with preprogrammed
data stored in an EEPROM within the module. The
module receives this data via the signal line from the
sensor and calculates the distance to the obstacle
according to the elapsed time between the transmitted
and received impulse. The duration of the impulse
transmission is determined by the module. The
frequency of the impulse is determined by the sensor.
In the receiver mode, the sensor will receive impulses
that were emitted by adjacent sensors. The module uses
this information to precisely determine position and
distance of the obstacle.
(G421252) Technical Training114
Lesson 2 – ElectricalParking Aid 
						

							PARKING AID SWITCH
Switch1LED2
The parking aid switch is located in the centre console,
above the integrated head unit, to the left of the hazard
warning flasher switch. The switch is a non-latching
switch with an integral LED. The switch receives a 12V
output to drive the LED when required. The switch is
also connected to ground. When the switch is operated,
the momentary completion of the ground is interpreted
by the parking aid module as a signal to enable or
disable the parking aid system.
Parking AidLesson 2 – Electrical
115Technical Training (G421252) 
						

							PARKING AID SOUNDER
The parking aid sounder is controlled by the parking
aid module and emits a series of tones of varying
frequency to inform the driver of the distance between
the vehicle and a detected object.
The rear parking aid sounder is located in the LH side
of the luggage compartment, behind the side trim panel,
below the window. The sounder is secured with two,
self tapping screws into the body. The sounder is
connected to the parking aid module via a harness
connector.
The front parking aid uses the instrument cluster sounder
and is activated by CAN messages from the parking aid
module to the instrument cluster.
PARKING AID OPERATION AND
DISTANCE CALCULATION
On vehicles with rear only parking aid sensors, when
the ignition switch is in position II and reverse gear is
selected, the parking aid sensors are automatically
activated. The parking aid module only activates the
system if reverse is selected for more than 1 second.
This avoids nuisance audible warnings when the gear
selector lever is being moved between Drive and Park
on vehicles with automatic transmission.
When the rear system is activated, the parking aid
module illuminates the indicator LED in the parking
aid switch, switches on the ultrasonic sensors and
generates a single chime on the parking aid sounder to
indicate the system is active. If an object is in the range
of the sensors when the system is activated, a series of
audible warnings are emitted by the parking aid sounder
immediately.
If parking aid operation is not required, it can be
suspended temporarily by pressing the parking aid
switch. On vehicles with rear only parking aid sensors,
the system can be enabled again by pressing the switch
again or switching the ignition off then on. The parking
aid will then automatically become active again in
reverse gear. The system also remains on when going
from reverse gear to neutral. The assumption being that
the driver may still want to manoeuvre the vehicle going
backwards in neutral.
(G421252) Technical Training116
Lesson 2 – ElectricalParking Aid 
						

							The parking aid module receives a signal on the CAN
from the central junction box when a trailer is fitted.
When this signal is detected, the parking aid module
suspends operation of the rear parking aid sensors.
On vehicles with front and rear systems, the front system
is activated when the ignition switch is in position II,
the vehicle is out of Park and the Electric Park Brake
(EPB) is off. If the vehicle speed subsequently goes
above approximately 10 mph (16 km/h), the front system
will switch off. When the speed drops below
approximately 6 mph (16 km/h), the front system
activates again. If the EPB is applied or Park is selected,
the Parking Aid system is deactivated.
Sensor Operation
The parking aid module processes the distance readings
from the ultrasonic sensors to determine if there are any
objects within the detection areas. If there are no objects
in the detection areas, there are no further audible
warnings. If an object is detected, repeated audible
warnings are produced on the parking aid sounder.
The maximum detection range is 1800 mm (70 in).
When an object is detected, the time delay between the
audible warning tones decreases as the distance between
the detected object and the vehicle decreases until, at
approximately 350 mm (13.7 in), the audible warning
tone is continuous.
After the initial detection of an object, if there is no
decrease in the distance between an object and the
central sensors, the time delay between the audible
warnings remains constant. If an object is detected by
one of the corner sensors only, the audible warnings
stop after about 5 seconds if there is no change in the
distance between the object and the corner sensor.
Parking AidLesson 2 – Electrical
117Technical Training (G421252) 
						

							Detection Area
Intermittent Warning ToneAContinuous Warning ToneB
Detection Calculation
When operating in the combined transmitter and receiver
mode, the sensor outputs a number ultrasonic pulses
and receives the reflected echo signal. The parking aid
module amplifies the received echo signals and
compares them with a preprogrammed threshold to
calculate the distance to the object. This is achieved by
determining the elapsed time between the transmission
and reception of the ultrasonic signal.
When operating in receiver mode, the sensor receives
echo signals transmitted by an adjacent sensor. This
mode is used to improve the accuracy of the system.
The detection cycle consists of the parking aid module
operating one sensor in the combined transmitter and
receiver mode and transmitting a number of ultrasonic
pulses. The module then switches the transmitting sensor
and the adjacent sensor(s) to receiver mode. After a
short time delay, this sequence is repeated using a
different sensor to transmit the ultrasonic pulse and
continues until all four sensors have output an ultrasonic
signal. This sequence is completed in 100ms. The
module uses several measurements of the same sensors
to remove errors from the calculation.
If the object is directly behind a sensor, the distance is
calculated using the time between the transmission and
reception of the signal. If the object is positioned
between two sensors, the parking aid module uses both
signals to determine the correct distance using
triangulation.
To perform the triangulation calculation, the parking
aid module must know the distance between the
individual sensors in the bumper. This information is
(G421252) Technical Training118
Lesson 2 – ElectricalParking Aid 
						

							stored in the module memory. From the received
distance from each sensor and using the known distance
between adjacent sensors, the module can calculate the
minimum distance from the vehicle to the object.
When approaching several objects, the module
recognises the distance from the vehicle to the nearest
object.
CONTROL DIAGRAM
NOTE: A  = Hardwired; N  = Medium Speed CAN Bus
Parking AidLesson 2 – Electrical
119Technical Training (G421252) 
						

							Fusible link 11E (30A)1
Ignition switch2
Fuse 36P (5A)3
Rear parking aid sounder4
Parking aid module5
Instrument cluster6
(G421252) Technical Training120
Lesson 2 – ElectricalParking Aid