Engine Control Module (ECM) 2.7L (Discovery 3)

ECM (engine control unit) is located in the mounting box in the chamber on the right side of the engine compartment, fixed to the partition.

Mounting box

Item name	Spare part catalog number	Description
1		Fan of the control system mounting box
2		ECM (engine control unit)
3		Transfer case controller

Input signals

To the ECM input (engine control unit) the following signals are received:

The article was taken from this resource: LRMAN.RU

• Coolant temperatures
• Clutch switch (via the parking brake controller)
• Brake light switch (via ABS control unit) (anti-lock braking system) via CAN bus (local area network of controllers))
• Manifold Absolute Pressure
• Accelerator pedal positions 1
• Accelerator pedal positions 2
• Electronic throttle positions
• Viscous coupling fan speeds
• Engine Crankshaft Position and Speed Sensor (crankshaft sensor)
• Camshaft position sensor
• Engine oil temperatures
• Cruise control speed switches (resistive multi-link chains)
• Vehicle speeds (via CAN bus) (local area network of controllers))
• Generator control circuits
• Airbag and seat belt system module
• Manifold absolute pressure and intake air temperature

Output signals

ECM Block (engine control unit) generates output signals to control the following components and parameters:

• Throttle actuator
• Nozzles (6 pieces)
• EGR valves (exhaust gas recirculation systems)
• Cooling system fan
• Fuel pump relay
• Starter relay
• Air Conditioner Condenser Fan Module
• EMS power relay
• Control of the viscous clutch of the cooling system fan
• Generator control

To the ECM on-board network (engine control unit) connected via three connectors. In ECM (engine control unit) contains processors and memory microchips. Output signals for actuators are provided by grounding the circuits with ECM control circuits (engine control unit). ECM control circuits (engine control unit) during normal operation, they generate heat and dissipate it through the housing. A fan in the electronic box helps with the cooling process, maintaining a constant temperature in the box. The fan is controlled by a thermostat located in the junction box. The junction box is connected to the car's interior and receives additional cool air through the A/C system. Some sensors receive regulated voltage supplied by the ECM. (engine control unit). This measure allows to avoid signal distortion caused by voltage drop when the engine is cranked by the starter.

ECM (engine control unit) performs self-diagnostic routines and stores fault codes in memory. These fault codes and diagnostics can be accessed using the Land Rover approved diagnostic system. If the ECM (engine control unit) needs to be replaced, new ECM module (engine control unit) must be programmed using a Land Rover approved diagnostic system as it is supplied unprogrammed. EEPROM Electrically Erasable Programmable Read Only Memory (flash memory) using the Land Rover approved diagnostic system, allows the ECM configuration to be adjusted up to 14 times (engine control unit) in accordance with market specifics or new regulatory information. If the 15th software update is required, ECM (engine control unit) must be replaced. Current engine tuning parameter values can be retrieved and read using the Land Rover approved diagnostic system.



When installing a new ECM (engine control unit) it must also be synchronised with the anti-theft alarm control module using a Land Rover approved diagnostic system. The ECM must not be interchanged (engine control unit) different cars.

ECM (engine control unit) is connected to engine sensors that allow it to monitor the engine's operating mode. ECM (engine control unit) processes sensor signals and decides what actions need to be taken to maintain optimum engine performance in terms of overall vehicle drivability, fuel economy and emissions. In the ECM's memory (engine control unit) during programming, instructions are entered with an algorithm for controlling the engine, called a control strategy. In addition, the memory contains data in the form of special tables, on the basis of which the ECM (engine control unit) delivers fuel and reduces exhaust toxicity. By comparing information from sensors with data from ECM tables (engine control unit) is capable of generating requirements for the operation of various systems. ECM (engine control unit) contains an adaptive strategy that updates the system when its elements change due to manufacturing tolerances or aging.

ECM (engine control unit) receives vehicle speed signal via CAN bus (local area network of controllers) from ABS control module (anti-lock braking system)Vehicle speed is an important input signal for ECM strategies. (engine control unit). ABS control module (anti-lock braking system) determines the speed signal based on signals from the ABS wheel speed sensors (anti-lock braking system). The frequency of these signals depends on the driving speed. ECM (engine control unit) uses this signal to determine the following:

• How much to reduce engine torque when changing gears.
• When to enable speed control operation.
• To control the operation of the speed control system.
• Controlling idle speed when the vehicle is stationary.

ECM Wiring Harness Connector C0872 Pins

Contact No.	Purpose	Input signal/output signal
A1	Serial communication line with the immobilizer control unit	Output signal
A2	Serial communication line with the immobilizer control unit	Input signal
A3	CAN bus low level signal (local area network of controllers)	Input signal/output signal
A4	CAN bus high level signal (local area network of controllers)	Input signal/output signal
B1	Starter operation permission	Output signal
B2	APP sensor mass (accelerator pedal position)	-
B3	Radiator outlet temperature sensor mass	-
B4	Cruise control	Input signal
C1	APP sensor mass (accelerator pedal position) 1	-
C2	APP sensor reference voltage (accelerator pedal position) 2	Output signal
C3	ECT sensor (coolant temperature)	Output signal
C4	Cruise control	Input signal
D1	APP sensor signal (accelerator pedal position) 1	Input signal
D2	APP sensor mass (accelerator pedal position) 2	-
D3	Voltage 2	Input signal
D4	Not used	-
E1	APP sensor reference voltage (accelerator pedal position) 1	Output signal
E2	Water in fuel sensor	Input signal
E3	Brake switch 1	Input signal
E4	Inertia switch	Input signal
F1	Intake Air Temperature Sensor	Input signal
F2	Not used	-
F3	Engine cranking signal	Input signal
F4	Mass air flow sensor.	Input signal
G1	Fuel pump supply control	Input signal
G2	Brake light switch	Input signal
G3	Not used	-
G4	Not used	-
H1	Not used	-
H2	Not used	-
H3	Not used	-
H4	Not used	-
J1	Not used	-
J2	Fan of the control system mounting box	Output signal
J3	Power relay	Output signal
J4	Fuel pump relay	Output signal
K1	Not used	-
K2	Electric cooling fan control	Output signal
K3	Sensor in the ignition switch	Input signal
K4	Power in standby mode	Input signal
L1	Battery voltage	Input signal
L2	Battery voltage	Input signal
L3	Battery voltage	Input signal
L4	Weight	-
M1	Weight	-
M2	Weight	-
M3	Weight	-
M4	Weight	-

ECM Wiring Harness Connector C0411 Pins

Contact No.	Purpose	Input signal/output signal
A1	Engine oil temperature sensor	Input signal
A2	Not used	-
A3	Not used	-
A4	Not used	-
B1	Backup analog input	Input signal
B2	Backup analog input	Output signal
B3	CAN bus low level signal (local area network of controllers)	Input signal/output signal
B4	CAN bus high level signal (local area network of controllers)	Input signal/output signal
C1	Not used	Input signal
C2	Sensor mass
C3	Not used
C4	Knock sensor row B (-)	Input signal
D1	Fuel rail pressure sensor signal	Input signal
D2	Fuel Rail Pressure Sensor	Output signal
D3	Knock sensor row B (+)	Output signal
D4	Knock sensor row A (-)	Input signal
E1	Throttle position sensor	Input signal
E2	Fuel Rail Pressure Sensor Mass	-
E3	Glow plug power supply control for row A	Input signal
E4	Knock sensor row A (+)	Input signal
F1	Electronic throttle voltage	Output signal
F2	Electronic throttle body weight	-
F3	Checking the glow plugs of row B	Input signal
F4	Backup PWM output signal (pulse width modulation)	Output signal
G1	Active Engine Suspension Control 1	Output signal
G2	Active Engine Suspension Control 2	Output signal
G3	Glow Plug Relay Control	Output signal
G4	Not used	-
H1	Generator Team	Output signal
H2	Not used	-
H3	Not used	-
H4	Not used	-
J1	Not used	-
J2	Fan of the control system mounting box
J3	Power relay	Output signal
J4	Fuel supply control valve	Output signal
K1	Engine oil temperature sensor mass	-
K2	Viscous Clutch Fan Control	Output signal
K3	Fuel pressure control valve	Input signal
K4	Intake Port Shut-Off Drive	Output signal
L1	Injector command 1	Output signal
L2	Common Nozzle 1	-
L3	Common Nozzle 3	-
L4		Output signal
M1	Injector command 3	Output signal
M2	Injector command 5	Output signal
M3	Total Nozzle 5	-
M4	Mass 7	-

ECM Wiring Harness Connector C2518 Pins

Contact No.	Purpose	Input signal/output signal
A1	Backup analog input	-
A2	EGR valve position sensor (exhaust gas recirculation systems) row B	Input signal
A3	EGR valve position sensor (exhaust gas recirculation systems) row A	Input signal/output signal
A4	Not used	Input signal/output signal
B1	Charge air temperature sensor	Input signal
B2	Fuel temperature sensor	Input signal
B3	Not used	-
B4	Not used	-
C1	Manifold Absolute Pressure Sensor	Input signal
C2	Engine Coolant Temperature Sensor	-
C3	Analog voltage 1	Input signal
C4	VGT row A	Input signal
D1	Supply for the absolute pressure sensor in the manifold	Output signal
D2	Sensor mass M	Output signal
D3	Not used
D4	Not used
E1	Engine cooling system fan control device	Input signal
E2	Not used	-
E3	Not used	-
E4	Not used	-
F1	Crankshaft position sensor	Input signal
F2	Generator load sensor signal	Input signal
F3	Not used	-
F4	Not used	-
G1	Power supply for crankshaft position sensor	Output signal
G2	Crankshaft Position Sensor Mass	-
G3	Variable Geometry Turbine Drive Mass	-
G4	Camshaft sensor signal	Input signal
H1	EGR (exhaust gas recirculation systems) row A (+)	Output signal
H2	EGR (exhaust gas recirculation systems) row A (-)	-
H3	Camshaft Position Sensor Mass	-
H4	Power supply for the camshaft position sensor	Output signal
J1	EGR (exhaust gas recirculation systems) row B (+)	Output signal
J2	VGT row A (+)	Output signal
J3	Not used	Output signal
J4	Throttle actuator (+)	Output signal
K1	EGR (exhaust gas recirculation systems) row B (-)	-
K2	VGT (-)	-
K3	Not used	Input signal
K4	Throttle actuator (-)	-
L1	Not used	-
L2	Common injector 2	-
L3	Total injector 0	-
L4	Common injector 4	-
M1	Power circuit mass	-
M2	Injector command 2	Output signal
M3	Injector command 0	Output signal
M4	Injector command 4	Output signal

Blocking unauthorized launch

The IMMOBILIZER control unit receives data from the relevant vehicle systems and transmits a coded signal to the ECM (engine control unit) to allow the engine to start if all conditions for this are met. The data is decoded by the ECM (engine control unit), and if they are correct, the engine starts.

The data is a continuously changing code, so the immobilizer control unit and ECM (engine control unit) must be synchronized in case of replacement of any of the devices.

In addition, ECM (engine control unit) protects the starter from accidental activation. The IMMOBILIZER control unit receives the engine crankshaft speed signal from the ECM via the instrument cluster (engine control unit). If the engine speed exceeds a preset value, the immobilizer control unit prohibits the starter operation via the built-in starter interlock relay. For more information, refer to AntiTheft - Passive (419-01B Anti-Theft - Passive)