Land Rover Range Rover Electrical Library Lm 2nd Edition Rover Manual

							DESCRIPTION AND OPERATION
4.36RANGE ROVER
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fuse 25 and fuse 53 of the 
passenger compartment fuse box (C0632) on an R wire. Fuse 53 (C0583) is connected to 
the ignition switch (C0028) by an RU wire. When the ignition switch is turned to the ignition 
position, current flows across the switch (C0028) to fuse 5 of the passenger compartment 
fuse box (C0585) on a G wire. Fuse 5 (C0587) provides an ignition feed to the alternator 
(C0053) on a GW wire.
Fuse 25 of the passenger compartment fuse box (C0583) is connected to the ignition switch 
(C0028) by an R wire. When the ignition switch is turned to the crank position, current flows 
across the switch (C0028) to the Engine Control Module (ECM) (C0331) on a BY wire, and 
the ignition coil relay (C2089) on a G then GN wire.
Starting
Starter Motor
The starter motor solenoid (C0178) is provided a constant battery feed from the battery 
(C0192) on an R wire. If all parameters for starting have been met, the ECM (C0331) 
provides a feed to the automatic transmission interlock relay (C1455) on a YN wire. If the 
gear selector lever is in Park or Neutral, the interlock relay (C1455) provides a feed to the 
starter solenoid (C0179) on a B then BY wire. The energised starter solenoid allows the 
battery feed to power the starter motor.
The starter motor (C0179) also provides an engine start signal back to the ECM (C0606) 
on a BG wire.
Ignition Coils
The ignition coil relay (C2089) receives an engine crank feed from the ignition switch 
(C0028) on a GN wire. The relay coil (C2089) is earthed on an N wire. The energised ignition 
coil relay (C2089) provides a feed to the following on G wires:

Ignition coil 1 (C0156).

Ignition coil 2 (C0052).

Ignition coil 3 (C0276).

Ignition coil 4 (C1770).

Ignition coil 5 (C1771).

Ignition coil 6 (C1772).

Ignition coil 7 (C2087).

Ignition coil 8 (C2088).
Fuel Pump
When the engine is started, the ECM (C0331) provides an earth path for the fuel pump relay 
coil (C2022) on a BP wire. The energised fuel pump relay (C2020) provides a feed to the 
fuel pump (C0114) on a WU wire. The fuel pump (C0114) is earthed on an N wire. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.37
Charging
The battery (C0192) provides a permanent feed to the alternator (C0183) on an R wire. Fuse 
5 of the passenger compartment fuse box (C0587) provides an ignition feed to the alternator 
(C0053) on a GW wire. 
When the engine is cranked, the alternator (C0053) supplies the ECM (C0606) a Pulse 
Width Modulated (PWM) signal on a U wire. The ECM uses this PWM signal to calculate the 
electrical load on the alternator, and controls engine idle speed accordingly.
When the engine is started, the magnetised rotor within the stator windings generate 3 
phase alternating current (ac) and voltage that rises rapidly with rotor speed. The field 
diodes in the rectifier pack convert the ac current into direct current (dc). Output current from 
the field diodes supplements the initial current flowing through the field windings. This 
causes an increase in the magnetic influence of the rotor, resulting in self-exitation of the 
alternator. The field current increases with rotor speed and thus increases the generated 
current and voltage until the alternator is fully excited. The alternator (C0183) charges the 
battery (C0192) by providing current on an R wire. 
						

							DESCRIPTION AND OPERATION
4.38RANGE ROVER
CRUISE CONTROL
DESCRIPTION
General
The cruise control system is enabled by pressing the non-latching master switch located on 
the LH steering wheel switch pack. The system is controlled by the Engine Control Module 
(ECM), which receives commands from the SET+ and RES switches, which are also 
located on the LH steering wheel switch pack. The ECM interprets the messages sent from 
the steering wheel switches and then controls the speed of the vehicle using electric throttle 
intervention.
For a detailed description of cruise control operation, refer to the Engine Management – 
Td6  or  Engine Management – V8  section of the Description and Operation Workshop 
Manual.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fuse 53 of the passenger 
compartment fuse box (C0632) on an R wire. Fuse 53 (C0583) is connected to the ignition 
switch (C0099 on Td6 vehicles, C0028 on V8 vehicles) by an R wire. When the ignition 
switch is turned to the auxiliary position, current flows across the switch (C0099 on Td6 
vehicles, C0028 on V8 vehicles) to fuse 9 of the passenger compartment fuse box (C0585) 
on a PB wire. Fuse 9 (C0587) provides an auxiliary ignition feed to the rotary coupler 
(C0082) on a PY wire.
When the ignition switch is turned to the ignition position, current flows across the switch 
(C0099 on Td6 vehicles, C0028 on V8 vehicles) to fuse 31 of the passenger compartment 
fuse box (C0585) on a G wire. Fuse 31 (C0587) provides an ignition feed to the Engine 
Control Module (ECM) (C0331) on a GB wire.
Throttle Position (TP) Sensor
The TP sensor (C0787) comprises two potentiometer tracks. Track 1 is provided a 5V 
reference feed by the ECM (C0331) on a Y wire. Track 2 is provided a 5V reference feed by 
the ECM (C0331) on a YG wire. Track 1 provides a throttle position signal back to the ECM 
on a W wire. This signal will be approximately 0.5V with the pedal at rest, and 2V at full 
throttle. Track 2 provides a throttle position signal back to the ECM on a WG wire. This signal 
will be approximately 0.5V with the throttle at rest, and 4.5V at full throttle. The ECM also 
provides an earth path for track 1 and track 2 on NG and UG wires respectively.
For more information of TP sensor operation, refer to the  Engine Management – Td6  or  
Engine Management – V8  section of the System Description and Operation Workshop 
Manual. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.39
Brake Pedal Switch
Fuse 9 of the passenger compartment fuse box (C0586) provides an auxiliary ignition feed 
to the brake pedal switch (C0075) on a PY wire. When the brake pedal is pressed, the switch 
(C0075) provides the ECM (C0331) a voltage of between 6 V and battery voltage on an NS 
wire. When the pedal is released, the switch provides the ECM a voltage of between 
approximately 0 and 2 V. Once the ECM registers the brake pedal has been pressed, it will 
suspend cruise control operation.
The brake pedal switch (C0075) also provides a test signal to the ECM (C0331) on a UR 
wire. The switch (C0075) is earthed on an NB wire.
CAN Bus
When cruise control is activated, the ECM (C0331) informs the automatic transmission ECU 
via the CAN Bus on YN (low) and YB (high) wires. The automatic transmission ECU will 
change its shift patterns accordingly. For more information on automatic transmission 
operation, refer to the  Automatic Transmission – ZF 5HP24  or  Automatic 
Transmission – GM5L40–E  section of the System Description and Operation Workshop 
Manual, and the  Electronic Automatic Transmission – ZF  or  Electronic Automatic 
Transmission – GM5  section of this manual.
 
+  ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – ZF. 
 
+  ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – GM5. 
Rotary Coupler
The rotary coupler (C0082) receives an ignition feed from fuse 9 of the passenger 
compartment fuse box (C0587) on a PY wire, and is earthed on an NB wire. The rotary 
coupler (C2287) receives voltage pulse messages from the LH steering wheel module 
(C2283) as follows:

A cruise control on/off signal on a W wire.

A set/accelerate signal on a U wire.

A decelerate signal on an R wire.

A resume signal on a B wire.
The messages from the LH steering wheel module are relayed from the rotary coupler 
(C0082) to the ECM (C0331) on a YB wire. The ECM interprets this message and controls 
the throttle pedal accordingly. 
						

							DESCRIPTION AND OPERATION
4.40RANGE ROVER
ELECTRONIC AUTOMATIC TRANSMISSION (EAT) – GM5
DESCRIPTION
General
The GM 5L40-E transmission is an electrically controlled, five speed unit and is mated with 
the Td6 diesel engine. The transmission is controlled by an Electronic Automatic 
Transmission (EAT) ECU which contains software to provide operation as a semi-automatic 
Steptronic transmission. This allows the transmission to be operated as a conventional 
automatic unit by selecting P, R, N, or D on the selector lever. Movement of the selector 
lever across the gate to the M/S position puts the transmission into electronic sport mode. 
Movement of the selector lever in a lateral position to the + or – positions puts the 
transmission into electronic manual Steptronic mode.
For a detailed description of GM5 automatic transmission operation, refer to the  Automatic 
Transmission – GM 5L40–E  section of the System Description and Operation Workshop 
Manual.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fuse 53 and fuse 54 of the 
passenger compartment fuse box (C0632) and the fuse holder (C1875) on R wires. The 
100A fuse located in the fuse holder (C1878) provides a constant battery feed to the Engine 
Control Module (ECM) relay (C1895) on an R wire. The 50A fuse located in the fuse holder 
(C1876) provides a constant battery feed to the transfer box ECU (C1855) on a pair of R 
wires.
Fuse 54 of the passenger compartment fuse box (C0583) provides a constant battery feed 
to the EAT ECU (C0932) on a RY wire. Fuse 53 of the passenger compartment fuse box 
(C0583) provides a constant battery feed to the ignition switch (C0099) on an R wire. When 
the ignition switch is turned to the auxiliary position, current flows across the switch (C0099) 
to fuse 37 of the passenger compartment fuse box (C0585) on a PB wire. Fuse 37 (C0587) 
provides an ignition feed to the transfer box ECU (C1319) on a PU wire.
When the ignition switch is turned to the ignition position, current flows across the switch 
(C0099) to fuse 5, fuse 33, and fuse 35 of the passenger compartment fuse box (C0585) on 
a G wire. Fuse 5 (C0587) provides an ignition feed to the EAT ECU (C0932) on a GW wire. 
Fuse 33 (C0587) provides an ignition feed to the transfer box ECU (C1319) on a GP wire. 
Fuse 35 (C0587) provides an ignition feed to the Hill Descent Control (HDC) switch (C0365) 
on a GBY wire. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.41
ECM Relay
The ECM (C0604) provides an earth path for the ECM relay coil (C1895) on an N wire. The 
energised relay (C1895) provides a feed to fuse 2 of the engine compartment fuse box 
(C0570) on an RW wire. Fuse 2 (C0570) is connected to the EAT ECU (C0932) by a pair of 
RU wires.
For more details on ECM relay operation, refer to the  Engine Management System – Td6  
section of the System Description and Operation Workshop Manual.
EAT ECU
The EAT ECU controls operation of the transmission via the following:
Pressure Regulator Solenoid
The EAT ECU (C1835) provides a Pulse Width Modulated (PWM) signal to the pressure 
regulator solenoid (C0244) on a P wire. This enables the pressure regulator solenoid (in 
conjunction with the pressure regulator valve) to control line pressure supplied to the 
clutches and shift control valves. The EAT ECU (C1835) provides an earth path for the 
pressure regulator solenoid (C0244) on an R wire.
Torque Converter Clutch (TCC) Solenoid
The EAT ECU (C1835) provides a PWM signal to the TCC solenoid (C0244) on a G wire. 
The TCC solenoid is a normally closed solenoid, and controls the output fluid pressure to 
the torque converter clutch. The EAT ECU (C1835) provides an earth path for the TCC 
solenoid (C0244) on a BY wire.
Shift Control Solenoids
The EAT ECU (C1835) provides a PWM signal to the three identical shift control solenoids 
(C0244) on a G wire. The EAT ECU (C1835) provides an earth path for solenoid A (C0244) 
on an OB wire, solenoid B (C0244) on a GR wire, and solenoid C (C0244) on a Y wire. For 
details of solenoid opening and closing, refer to the  Automatic Transmission – GM 5L40–
E  section of the System Description and Operation Workshop manual.
Input Shaft Speed Sensor
The EAT ECU (C1835) provides a feed to the input shaft speed sensor (C0244) on a U wire. 
The input shaft speed sensor (C0244) returns an ac voltage pulse back to the EAT ECU 
(C1835) on an O wire. By measuring the peak to peak voltage of the voltage wave form, the 
EAT ECU can determine the speed of the input shaft.
Output Shaft Speed Sensor
The EAT ECU (C1835) provides a feed to the output shaft speed sensor (C0244) on a W 
wire. The output shaft speed sensor (C0244) returns an ac voltage pulse back to the EAT 
ECU (C1835) on an N wire. By measuring the peak to peak voltage of the voltage wave form, 
the EAT ECU can determine the speed of the output shaft. 
						

							DESCRIPTION AND OPERATION
4.42RANGE ROVER
Transmission Temperature Sensor
The temperature of the Automatic Transmission Fluid (ATF) is measured by the Negative 
Temperature Coefficient (NTC) transmission temperature sensor. The EAT ECU (C1835) 
provides a feed to the temperature sensor (C0244) on a BR wire. By measuring the voltage 
returned on a WR wire, the EAT ECU can determine ATF temperature.
Inhibitor Switch
The inhibitor switch is mounted on the LH side of the transmission, and enables the EAT 
ECU to monitor the position of the manual selector spool valve and the selected drive 
program. The EAT ECU (C1835) provides an ignition feed to the inhibitor switch (C0244) on 
a YB wire. When Park or Neutral is selected, the inhibitor switch (C0244) returns a feed back 
to the EAT ECU (C1835) on an O wire. When Drive is selected, the inhibitor switch (C0244) 
returns a feed back to the EAT ECU (C1835) on a B wire. 
When shift solenoid A is energised, the inhibitor switch (C0244) returns a feed back to the 
EAT ECU (C1835) on a PW wire. When shift solenoid B is energised, the inhibitor switch 
(C0244) returns a feed back to the EAT ECU (C1835) on a YB wire. When shift solenoid C 
is energised, the inhibitor switch (C0244) returns a feed back to the EAT ECU (C1835) on a 
TB wire.
NOTE: Wire colour TB is transparent with a black tracer.
Shift Interlock Solenoid
To lock the selector lever assembly, the EAT ECU (C0193) provides a feed to the shift 
interlock solenoid (C0673) on a BP wire. An earth path is provided by the EAT ECU (C0193) 
on an NP wire.
Steptronic
When manual (Steptronic) mode is selected, the EAT ECU selects gears according to inputs 
received from the Steptronic switch. The EAT ECU (C0193) provides two feeds to the 
Steptronic switch (C1664); one on a UY wire, one on a US wire. If a downshift is requested 
via the selector lever, a momentary earth is created. Current on the UY wire is allowed to 
flow across the switch to earth on an NB wire. Sensing this, the EAT ECU downshifts 1 gear.
If an upshift is requested via the selector lever, a momentary earth is created. Current on the 
US wire is now allowed to flow across the switch to earth on an NB wire. Sensing this, the 
EAT ECU upshifts 1 gear. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.43
ELECTRONIC AUTOMATIC TRANSMISSION  (EAT) – ZF
DESCRIPTION
General
The ZF 5HP24 transmission is an electronically controlled, five speed unit and is mated with 
the V8 petrol engine. The transmission is controlled by an Electronic Automatic 
Transmission (EAT) ECU, which contains software to provide operation as a semi-automatic 
Steptronic transmission. This allows the transmission to be operated as a conventional 
automatic unit by selecting P, R, N, or D on the selector lever. Movement of the selector 
lever across the gate to the M/S position puts the transmission into electronic Sport mode. 
Movement of the selector lever in a lateral position to the + or – positions puts the 
transmission into electronic manual Steptronic mode.
For a detailed description of ZF automatic transmission operation, refer to the  Automatic 
Transmission – ZF 5HP24  section of the System Description and Operation Workshop 
Manual.
OPERATION
Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 2 and fuse 53 of 
the passenger compartment fuse box (C0632) on an R wire. A permanent battery feed is 
also supplied to the 50A fuse contained within the fuse holder (C1875) on an R wire. This 
fuse (C1876) provides a constant battery feed to the transfer box ECU (C1855) on a pair of 
R wires.
Fusible link 2 of the passenger compartment fuse box (C0591) provides a constant battery 
feed to the ECM relay (C1895) and fuse 4 of the engine compartment fuse box (C0570) on 
a pair of R wires. Operation of the ECM relay (C1895) is controlled by the ECM (C0604) on 
an N wire. The energised ECM relay (C1895) provides a feed to fuse 1 of the engine 
compartment fuse box (C0570) on an RW wire. Fuse 1 (C0570) is connected to the EAT 
ECU (C0932) by a pair of RU wires. The EAT ECU (C0932) is earthed on N wires.
Fuse 4 of the engine compartment fuse box (C0570) is connected to the EAT ECU (C0932) 
by an R wire.
Fuse 53 of the passenger compartment fuse box (C0583) is connected to the ignition switch 
(C0099) by an R wire. When the ignition switch is turned to the auxiliary position, current 
flows across the switch (C0099) to fuse 37 of the passenger compartment fuse box (C0587) 
on a PB wire. Fuse 37 (C0587) provides an auxiliary ignition feed to the transfer box ECU 
(C1319) on a PU wire. 
						

							DESCRIPTION AND OPERATION
4.44RANGE ROVER
When the ignition switch is turned to the ignition position, current flows across the switch 
(C0099) to fuse 5, fuse 33, and fuse 35 of the passenger compartment fuse box (C0585) on 
a G wire. Fuse 5 (C0587) provides an ignition feed to the EAT ECU (C1835) on a GW wire. 
Fuse 33 (C0587) provides an ignition feed to the transfer box ECU (C1319) on a GP wire. 
Fuse 35 (C0587) provides an ignition feed to the Hill Descent Control (HDC) switch (C0365) 
on a GBY wire.
EAT ECU
The EAT ECU controls operation of the transmission via the following:
Electronic Pressure Regulator Solenoids (EPRS)
The five EPRS located in the automatic transmission (C0244) are provided a Pulse Width 
Modulated (PWM) by the EAT ECU (C1835) on a P wire. The EAT ECU controls operation 
of the EPRS by providing earth paths on TB, R, B, K and YR wires.
NOTE: Wire colour TB is transparent with a black tracer.
Shift Control Solenoids
The three shift control solenoids located in the automatic transmission (C0244) are provided 
a feed by the EAT ECU (C1835) on a YU wire. The EAT ECU (C1835) energises the 
solenoids by providing earth paths on O, G, and Y wires.
Turbine Speed Sensor
The turbine speed sensor acts as an input speed sensor. The EAT ECU (C1835) provides 
a feed to the turbine speed sensor (C0244) on a U wire. The turbine speed sensor (C0244) 
returns an ac voltage pulse back to the EAT ECU (C1835) on an S wire. By measuring the 
peak to peak voltage of the voltage wave form, the EAT ECU can determine the speed of 
the turbine.
Output Shaft Speed Sensor
The EAT ECU (C1835) provides a feed to the output shaft speed sensor (C0244) on a W 
wire. The output shaft speed sensor (C0244) returns an ac voltage pulse back to the EAT 
ECU (C1835) on an N wire. By measuring the peak to peak voltage of the voltage wave form, 
the EAT ECU can determine the speed of the output shaft.
Transmission Temperature Sensor
The temperature of Automatic Transmission Fluid (ATF) is measured by the Negative 
Temperature Coefficient (NTC) transmission temperature sensor. The EAT ECU (C1835) 
provides a feed to the temperature sensor (C0244) on a BR wire. By measuring the voltage 
returned on a WR wire, the EAT ECU can determine ATF temperature. 
						

							DESCRIPTION AND OPERATION
RANGE ROVER 4.45
Shift Interlock Solenoid
To lock the selector lever assembly, the EAT ECU (C0193) provides a feed to the shift 
interlock solenoid (C0673) on a BP wire. An earth path is provided by the EAT ECU (C0193) 
on an NP wire.
Steptronic
When manual (Steptronic) mode is selected, the EAT ECU selects gears according to inputs 
received from the Steptronic switch. The EAT ECU (C0193) provides two feeds to the 
Steptronic switch (C1664); one on a UY wire, one on a US wire. If a downshift is requested 
via the selector lever, a momentary earth is created. Current on the UY wire is allowed to 
flow across the switch to earth on an NB wire. Sensing this, the EAT ECU downshifts 1 gear.
If an upshift is requested via the selector lever, a momentary earth is created. Current on the 
US wire is now allowed to flow across the switch to earth on an NB wire. Sensing this, the 
EAT ECU upshifts 1 gear.