Land Rover Freelander 2002my Electrical Library 3rd Edition Rover Manual

							DESCRIPTION AND OPERATION
4.50FREELANDER 02MY
Instrument Pack
When cruise control is operational, the cruise control interface unit (C1959) sends a cruise 
active message to the instrument pack (C0230) via the CAN-BUS on YN (low) and YB (high) 
wires. This message is used to illuminate the cruise control lamp housed within the 
instrument pack. 
						

							DESCRIPTION AND OPERATION
FREELANDER 02MY 4.51
CRUISE CONTROL – KV6
DESCRIPTION
General
Cruise control is switched on by pressing the cruise control master switch mounted on the 
centre console. The Set + and Res switches mounted on the steering wheel allow the 
driver to either set the vehicle speed as required or resume the last cruising speed set.
The cruise control system uses mechanical, electrical and vacuum operated devices to 
maintain vehicle speed at a setting selected by the driver. As vehicle speed changes due to 
changes in road gradients, so the cruise control ECU operates the cruise control pump, 
continually moving the cruise control actuator to maintain the set vehicle speed.
Should the driver wish to increase the speed of the vehicle, the Set + switch should be 
pressed and held. The vehicle will accelerate until the switch is released. As the Set + 
switch is released, the cruise control ECU will store the new cruise speed in its memory.
With cruise control switched on, it is possible to press the accelerator pedal and accelerate 
through the memorised set speed. When the accelerator is released, the cruise control ECU 
will automatically return the vehicle to its set speed. 
Note: The cruise control system will only operate between speeds of 22 mph (35 km/h) and 
125 mph (200 km/h).
Cruise control operation can be suspended by one of the following ways:

By pressing the Res switch.

By pressing the brake pedal.

The gearbox is placed in park, neutral, or reverse.

Hill Descent Control (HDC) is active.

Engine revs are too high.
Under all these conditions, the cruise control set speed will be memorised. Cruise control 
operation can be resumed by pressing the Res switch.
Cruise control operation can be cancelled in one of two ways:

By pressing the cruise control master switch located on the centre console.

By switching the ignition off.
In both these cases, the cruise control set speed will be lost.
Warning: Do not switch off the vehicle ignition unless the vehicle is stationary and 
the handbrake is applied. 
						

							DESCRIPTION AND OPERATION
4.52FREELANDER 02MY
OPERATION
General
Feed from the positive battery terminal (C0192) is supplied to the horn relay and fusible link 
3 of the engine compartment fuse box (C0632) on an R wire. Fusible link 3 (C0571) is 
connected to the ignition switch (C0028) by an N wire. When the ignition switch is turned to 
the ignition position, current flows across the switch (C0028) to fuse 35 of the passenger 
compartment fuse box (C0588) on a G wire. Fuse 35 (C0580) provides an ignition feed to 
the following on W wires:

The cruise control master switch (C0749)

The cruise control interface unit (C1959)

The brake lamp switch (C0652).
The ignition switch (C0028) also provides a feed to fuse 2 of the passenger compartment 
fuse box (C0588) on an NW wire. Fuse 2 (C0580) provides an ignition feed to the brake 
pedal switch (C0075) on a G wire.
Cruise Control Master Switch
The cruise control master switch (C0749) is mounted in the centre console and is provided 
an ignition feed from fuse 35 of the passenger compartment fuse box (C0580) on a W wire. 
When the switch is pressed, current flows across the switch contacts (C0749) to the cruise 
control interface unit (C1959) and the cruise control ECU (C0239) on WY wires.
NOTE: When the cruise control system is switched off using the master switch, any stored 
road speed values will be lost.
Cruise Control ECU
When cruise control is activated, the cruise control ECU (C0239) receives a feed from the 
cruise control master switch (C0749) on a WY wire. The ECU (C0239) is earthed on a B wire. 
To enable it to control the cruise control system, the ECU receives a number of inputs from 
various sources as follows:
ABS ECU 
The ABS ECU (C0500 on 01MY vehicles, C0501 on 02MY vehicles) provides a pulsed 
wheel speed signal to the cruise control ECU (C0239) on a WO wire. The rate of pulses 
provided by the ABS ECU increases by 2.22 Hz for every mile per hour speed increase 
(approximately 8,000 pulses per mile travelled). This enables the cruise control ECU to 
calculate the road speed of the vehicle. If vehicle speed is outside the operating limits (see  
Description), the cruise control ECU will not activate the system.
NOTE: If the Cruise Control ECU fails to receive a pulsed wheel speed signal from the ABS 
modulator, cruise control will not operate.
For more information on ABS ECU operation, refer to the  Anti-lock Braking System (ABS) 
– 01MY , or  Anti-lock Braking System (ABS) – 02MY  section of this manual.
 
+  ANTI-LOCK BRAKING SYSTEM (ABS) – 01MY. 
 
+  ANTI-LOCK BRAKING SYSTEM (ABS) – 02MY.  
						

							DESCRIPTION AND OPERATION
FREELANDER 02MY 4.53
Set + Switch
The non latching Set + switch (C1254) is provided a feed via the horn relay (C0576) on a PY 
wire. When the switch is pulled back against spring pressure, the switch contacts close and 
a feed is provided to the cruise control ECU (C0239) via the rotary coupler (C0082) on a RW 
wire. 
If cruise control is active, and the switch is operated for the first time, the cruise control ECU 
will store the current vehicle speed in its memory and maintain that speed.
NOTE: The cruise control ECU will only store and maintain the vehicle speed if it is within 
the operating limits given in the Description section above.
If the switch is tapped a second time, the ECU will increase the vehicle speed by 1 mph. If 
the switch is pulled back and held against spring pressure, the vehicle will accelerate until 
the switch is released. The final vehicle speed in both instances will be stored in the cruise 
control ECU memory.
Res Switch
The non latching Res switch (C1254) is provided a feed via the horn relay (C0576) on a PY 
wire. When the switch is pulled back against spring pressure, the switch contacts close and 
a feed is provided to the cruise control ECU (C0239) via the rotary coupler (C0082) on a UW 
wire. 
If the Res switch is pulled back against spring pressure, the cruise control ECU will alter 
vehicle speed to reflect the vehicle speed held within its memory. If the Res switch is pulled 
back for a second time, cruise control operation will be suspended 
NOTE: If a road speed value is not held within the cruise control ECU memory, the ECU will 
not respond to the Res switch input. To enter a vehicle speed into the ECU memory, refer 
to the Set + Switch section above.
Brake Lamp Switch – 01MY Vehicles
The Hall effect brake lamp switch (C0652) is provided an ignition feed from fuse 35 of the 
passenger compartment fuse box (C0580) on a W wire. The switch (C0652) is earthed on a 
B wire. When the brake pedal is in its normal position, the switch provides the cruise control 
ECU (C0239) a low voltage (between approximately 0V and 2V) on a PG wire. When the 
brake pedal is pressed, this voltage rises to between approximately 6V and battery voltage. 
When the ECU registers this rise in voltage, it suspends cruise control operation.
The brake lamp switch (C0652) also provides a brake pedal status signal to the cruise 
control interface unit (C1959) on a GR wire. 
						

							DESCRIPTION AND OPERATION
4.54FREELANDER 02MY
Brake Lamp Switch – 02MY Vehicles
The Hall effect brake lamp switch (C0652) is provided an ignition feed from fuse 35 of the 
passenger compartment fuse box (C0580) on a W wire. The switch (C0652) is earthed on a 
B wire. When the brake pedal is in its normal position, the switch provides the cruise control 
interface unit (C1959) a low voltage (between approximately 0V and 2V) on a PG wire. 
When the brake pedal is pressed, this voltage rises to between approximately 6V and 
battery voltage. When the interface unit registers this rise in voltage, it suspends cruise 
control operation.
The brake lamp switch (C0652) also provides a brake pedal status signal to the cruise 
control interface unit (C1959) on a GR wire.
Interface Unit
The interface unit (C1959) provides a feed to the cruise control ECU (C0239) on a PG wire 
if the following conditions exist:

The cruise control master switch is depressed.

The brake pedal is not depressed.

HDC is not activated.

The gear selector lever is not in the park, neutral, or reverse positions.

Engine speed is below 6,496 rpm.
The cruise control ECU uses the feed provided by the interface unit to enable the cruise 
control pump. For more details on interface unit operation, refer to the  Interface Unit  
section below.
Interface Unit
Fuse 35 of the passenger compartment fuse box (C0580) provides an ignition feed to the 
interface unit (C1959) on a W wire. The interface unit is earthed on a pair of B wires, and 
receives inputs from a number of different components as follows:
Cruise Control Master Switch
When the cruise control master switch is depressed, it provides a feed to the interface unit 
(C1959) on a WY wire. 
Brake Lamp Switch – 01MY Vehicles
When the brake pedal is in its normal position, the switch (C0652) provides the interface unit 
(C1959) a low voltage (between approximately 0V and 2V) on a GR wire. When the brake 
pedal is pressed, this voltage rises to between approximately 6V and battery voltage.
Brake Lamp Switch – 02MY Vehicles
When the brake pedal is in its normal position, the switch (C0652) provides the interface unit 
(C1959) a low voltage (between approximately 0V and 2V) on GR and PG wires. When the 
brake pedal is pressed, this voltage rises to between approximately 6V and battery voltage. 
						

							DESCRIPTION AND OPERATION
FREELANDER 02MY 4.55
Engine Control Module (ECM)
The ECM (C0371) provides a feed to the interface unit (C1959) on a BU wire if the following 
conditions exist:

HDC is not activated.

The gear selector lever is not in the park, neutral, or reverse positions.

Engine speed is below 6,496 rpm.
For more information on the Siemens ECM, refer to the  Engine Management Systems – 
Siemens  section of the System Description and Operation Workshop manual.
Cruise Control Pump
When all conditions for cruise control activation have been met, the cruise control ECU 
(C0239) provides a feed to the cruise control pump motor (C0228) on a WU wire. The pump 
motor creates a vacuum in the pump actuator. For a detailed description of actuator 
operation, refer to the  Engine Management Systems – Siemens  section of the Workshop 
manual.
Current flow across the pump motor is controlled by the ECU (C0239) providing a varying 
Pulse Width Modulated (PWM) signal to the other side of the pump motor (C0228) on a BR 
wire. When the correct vehicle speed has been reached, the ECU (C0239) replaces the 
PWM feed with a continuous feed. As the potential difference across the pump motor is now 
0V, the pump motor stops operating.
To maintain the vacuum in the actuator, both the control and dump valves are closed by the 
ECU. To close the valves, the ECU (C0239) provides a feed to the control and dump valves 
(C0228) on a WU wire. Current flows across the control valve (C0228) to the ECU (C0239) 
on a PY wire. Current flows across the dump valve (C0228) to the ECU (C0239) on a BR 
wire.
NOTE: Both the control valve and the dump valve are normally open valves.
When a decrease in speed is requested, the control valve is opened to reduce the 
depression within the actuator. This is done by the ECU (C0239) providing a PWM signal to 
the control valve (C0228) on a PY wire. When the correct speed has been achieved, the 
PWM signal is withdrawn.
When cruise is cancelled, the ECU (C0239) withdraws the feed to the dump valve (C0228) 
on a WU wire. The dump valve now opens, allowing atmospheric pressure into the actuator.
Brake Pedal Switch
As a safety feature, the dump valve is opened if the brake pedal is depressed. If cruise 
control is active and the brake pedal is pressed, the brake pedal switch (C0075) provides a 
feed to the dump valve (C0228) on a GP wire. As the potential difference across the valve 
is 0V, the valve opens allowing atmospheric pressure into the actuator. 
						

							DESCRIPTION AND OPERATION
4.56FREELANDER 02MY
Electronic Automatic Transmission (EAT) ECU
When all conditions for cruise control activation have been met, the cruise control ECU 
(C0239) provides a feed to the EAT ECU (C0932) on a WU wire. When the EAT ECU 
receives this feed, it enters its cruise control mode. For more information on EAT operation 
refer to the  Electronic Automatic Transmission (EAT) – 01MY , or  Electronic 
Automatic Transmission (EAT) – 02MY  section of this manual.
 
+  ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – 01MY. 
 
+  ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – 02MY. 
Instrument Pack
When all conditions for cruise control activation have been met, the cruise control ECU 
(C0239) provides a feed to the cruise control LED mounted within the instrument pack 
(C0230) on a WU wire. The cruise control LED is provided an earth by the instrument pack 
(C0230) on a B wire.
Diagnostic Socket
The diagnostic socket (C0040) is connected to the cruise control ECU (C0239) by a K wire, 
enabling the ECU to be interrogated by TestBook or T4. 
						

							DESCRIPTION AND OPERATION
FREELANDER 02MY 4.57
ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – 01MY
DESCRIPTION
General
The Jatco 5–speed automatic transmission fitted to Freelander is controlled by an Automatic 
Transmission Control Unit (ATCU). The ATCU is located inside the engine E-box, and 
receives information from the following sources to calculate when to operate the solenoid 
valves contained within the gearbox to enable quick, smooth, quiet gear changes;

The Engine Control Module (ECM) via the CAN-BUS,

The instrument pack via the CAN-BUS,

The cruise control ECU,

The automatic transmission selector,

The brake pedal switch,

The automatic gearbox sensors.
The Jatco automatic gearbox also has a number of different operating modes. When the 
ignition switch is first turned to the ignition position, the gearbox will always revert to the 
Normal mode. For a full description of the 5–speed automatic transmission, refer to the  
Automatic Gearbox – Jatco section of the System Description and Operation Workshop 
manual. 
						

							DESCRIPTION AND OPERATION
4.58FREELANDER 02MY
OPERATION
General
Feed from the positive battery terminal (C0192) is supplied to the main relay and fusible link 
3 (C0632) on an R wire. Both are located in the engine compartment fuse box.
The battery also provides a feed to fusible link 4 of the engine compartment fuse box 
(C0632) on vehicles fitted with an instrument dimmer switch. For more information, refer to 
the  Interior Lamps  section of this manual.
 
+  INTERIOR LAMPS. 
Operation of the main relay (C0576 on Td4 vehicles, C0578 on KV6 vehicles) is controlled 
by the Engine Control Module (ECM) (C0603 on Td4 vehicles, C0371 on KV6 vehicles) on 
a WK wire. The energised main relay allows a battery feed to flow to fuse 4 of the engine 
compartment fuse box. Fuse 4 (C0575) provides a feed to the following on NK wires:

The Automatic Transmission Control Unit (ATCU) (C0932).

The transmission selector (C0244) (vehicles without instrument dimmer only).

The illumination relay (C1976) (vehicles with instrument dimmer only).

The Steptronic switches (C0410).
For further details of main relay operation, refer to the Engine Management – EDC  or  
Engine Management – Siemens (All Except NAS)  section of the System Description and 
Operation Workshop manual.
Fusible link 3 (C0571) is connected to the ignition switch (C0028) by an N wire. When the 
ignition switch is turned to the ignition position, current flows across the switch (C0028) to 
fuse 2 of the passenger compartment fuse box (C0588) on an NW wire. Fuse 2 (C0580) 
provides an ignition feed to the brake pedal switch (C0075) and the Hill Descent Control 
(HDC) relay (C0574) on a G wires. The HDC relay is located in the engine compartment fuse 
box.
When the ignition switch is turned to the ignition position, current is also supplied to fuse 35 
of the passenger compartment fuse box (C0588) on a G wire. Fuse 35 (C0580) provides an 
ignition feed to the following components on W wires:

The HDC relay (C0571).

The transmission inhibit switch (C0244). 
						

							DESCRIPTION AND OPERATION
FREELANDER 02MY 4.59
ATCU
The ATCU monitors the operation of the automatic gearbox via four sensors:

The temperature of the automatic transmission fluid (ATF) is measured by the fluid 
temperature sensor. The fluid temperature sensor (C0243) receives a feed from the 
ATCU (C0932) on a WK wire. The temperature sensor return (C0243) to the ATCU 
(C0932) is via a KB wire. As the temperature of the ATF rises, so the resistance of the 
sensor decreases. The ATCU registers this drop in resistance and calculates the 
temperature of the ATF accordingly. For more information on the fluid temperature 
sensor, refer to the  Automatic Gearbox – Jatco  section of the System Description 
and Operation Workshop manual.

Vehicle speed is measured by the vehicle speed sensor. The vehicle speed sensor 
(C0243) is connected to the ATCU (C0932) by a U wire. The speed sensor creates a 
sinusoidal waveform, with each positive phase of the waveform representing one tooth 
on the parking gear (19 per engine revolution). The ATCU uses this waveform to 
calculate vehicle speed. The sensor return (C0243) to the ATCU (C0932) is via a W 
then KB wire. For more information on the vehicle speed sensor, refer to the  
Automatic Gearbox – Jatco  section of the System Description and Operation 
Workshop manual.

Input shaft speed into the gearbox is measured by the turbine sensor. The turbine 
sensor (C0243) is connected to the ATCU (C0932) by an R wire. The turbine sensor 
creates a sinusoidal waveform, with 16 positive phases representing one input shaft 
revolution. The ATCU uses this signal along with a vehicle speed signal to calculate if 
the correct gear has been selected. The sensor return (C0243) to the ATCU (C0932) 
is via a U then KB wire. For more information on the turbine sensor, refer to the  
Automatic Gearbox – Jatco  section of the System Description and Operation 
Workshop manual.

The internal, or intermediate, transmission speed is measured by the intermediate 
sensor. The intermediate sensor (C0243) is connected to the ATCU (C0932) by an R 
wire. The intermediate sensor creates a sinusoidal waveform, with each positive phase 
of the waveform representing one tooth of the output gear (49 per revolution). The 
ATCU uses this signal to ensure the correct gear is engaged, and to monitor the 
amount of slip within the gearbox. The sensor return (C0243) to the ATCU (C0932) is 
via a B then KB wire. For more information on the intermediate sensor, refer to the  
Automatic Gearbox – Jatco  section of the System Description and Operation 
Workshop manual.
Park
When park is selected, a main relay feed is able to flow from the transmission selector/inhibit 
switch (C0244) to the ATCU (C0932) and the selector indicator (C0675) on a KO wire. The 
P symbol on the selector housing will now illuminate.