eft Contents Page
:  Mar 22, 2007



TDV6 ENGINE MANAGEMENT COMPONENT LOCATION - SHEET 1 of 2



1  - Knock sensors
2   Fuel rail pressure sensor
3   High pressure fuel pump
4   EGR (exhaust gas recirculation) Valve/cooler
5   Injector
6   Turbo boost pressure control
7   CKP (crankshaft position) sensor
8   Oil temperature sensor
9   CMP (camshaft position) sensor
10   MAF (mass air flow) /IAT (intake air temperature) sensor
11   Air charge temperature sensor
12   Glow plugs
13   Electronic throttle incorporating MAP (manifold absolute pressure) sensor
14   Glow plug wiring harness
15   ECT (engine coolant temperature) sensor

TDV6 ENGINE MANAGEMENT COMPONENT LOCATION - SHEET 2 of 2



1   Main relay
2   Transfer box control module
3   ECM (engine control module)
4   APP (accelerator pedal position) sensor
5   Stop lamp switch
6   Clutch switch
7   ABS (anti-lock brake system) Control module

TDV6 ENGINE MANAGEMENT CONTROL DIAGRAM - SHEET 1 of 2

:
  A = Hardwired; D = CAN (controller area network)



1   Glow plugs
2   E-box cooling fan
3   Port de-activation vacuum actuator
4   ABS (anti-lock brake system) control module
5   Instrument cluster
6   TCM (transmission control module)
7   RCM (restraints control module)
8   Transfer box control module
9   Differential control module
10   Electric park brake control module
11   Terrain Response™ control module
12   Turbo boost pressure controller
13   EGR (exhaust gas recirculation) valve/cooler
14   Generator
15   Steering wheel mounted speed control switches
16   Clock spring
17   ECM (engine control module)
18   Electric throttle valve
19   Injectors

TDV6 ENGINE MANAGEMENT CONTROL DIAGRAM - SHEET 2 of 2

:
  A = Hardwired



1   Main relay
2   CKP (crankshaft position) sensor
3   CMP (camshaft position) sensor
4   ECT (engine coolant temperature) sensor
5   APP (accelerator pedal position) sensor
6   MAF (mass air flow) /IAT (intake air temperature) sensor
7   Engine oil temperature sensor
8   Fuel rail temperature sensor
9   Boost pressure sensor
10   Boost air temperature sensor
11   RCM (restraints control module)
12   Stop lamp switch
13   Knock sensors
14   ECM (engine control module)
15   Fuse 60P
16   Fuse 25P
17   Ignition switch
18   Fuse 11E

OVERVIEW

The TDV6 engine has an Electronic Diesel Control (EDC) engine management system supplied by Siemens. The system is controlled by an ECM (engine control module) and is able to monitor, adapt and precisely control the fuel injection. The ECM (engine control module) uses multiple sensor inputs and precision control of actuators to achieve optimum performance during all driving conditions.

The ECM (engine control module) controls fuel delivery to all six cylinders via a Common Rail (CR) injection system. The CR system uses a fuel rail to accumulate highly pressurized fuel and feed the six, electronically controlled injectors. The fuel rail is located in close proximity to the injectors, which assists in maintaining full system pressure at each injector at all times.

The ECM (engine control module) uses the drive by wire principle for acceleration control. There are no control cables or physical connections between the accelerator pedal and the engine. Accelerator pedal demand is communicated to the ECM (engine control module) by two potentiometers located in a throttle position sensor. The ECM (engine control module) uses the two signals to determine the position, rate of movement and direction of movement of the pedal. The ECM (engine control module) then uses this data, along with other engine information from other sensors, to achieve the optimum engine response.

The ECM (engine control module) processes information from the following input sources:

The ECM (engine control module) outputs controlling signals to the following sensors and actuator:

ENGINE CONTROL MODULE (ECM)



The ECM (engine control module) is located in the E-Box in the plenum area on the RH side of the engine compartment attached to the bulkhead.

E Box



1   E box fan
2   ECM (engine control module)
3   Transfer box control module

Inputs

The ECM (engine control module) has the following inputs:

Outputs

The ECM (engine control module) outputs to the following:

The ECM (engine control module) connected to the vehicle harnesses via three connectors. The ECM (engine control module) contains data processors and memory microchips. The output signals to the actuators are in the form of ground paths provided by driver circuits within the ECM (engine control module) . The ECM (engine control module) driver circuits produce heat during normal operation and dissipate this heat via the casing. The fan in the E-box assists with the cooling process by maintaining a constant temperature with the E-box. The fan is controlled by a thermostatic switch located in the E-box. The E-box has pipe connections to the vehicle interior and receives additional cooled air via the A/C system. Some sensors receive a regulated voltage supplied by the ECM (engine control module) . This avoids incorrect signals caused by voltage drop during cranking.

The ECM (engine control module) performs self diagnostic routines and stores fault codes in its memory. These fault codes and diagnostics can be accessed using a Land Rover approved diagnostic system. If the ECM (engine control module) is to be replaced, the new ECM (engine control module) is supplied 'blank' and must be configured to the vehicle using a Land Rover approved diagnostic system. A 'flash' Electronic Erasable Programmable Read Only Memory (EEPROM) allows the ECM (engine control module) to be externally configured, using a Land Rover approved diagnostic system, with market specific or new tune information up to 14 times. If a fifteenth update is required the ECM (engine control module) must be replaced. The current engine tune data can be accessed and read using a Land Rover approved diagnostic system.

When a new ECM (engine control module) is fitted, it must also be synchronized to the immobilization control module using a Land Rover approved diagnostic system. ECM (engine control module) 's cannot be 'swapped' between vehicles.

The ECM (engine control module) is connected to the engine sensors which allow it to monitor the engine operating conditions. The ECM (engine control module) processes these signals and decides the actions necessary to maintain optimum engine performance in terms of driveability, fuel efficiency and exhaust emissions. The memory of the ECM (engine control module) is programmed with instructions for how to control the engine, this known as the strategy. The memory also contains data in the form of maps which the ECM (engine control module) uses as a basis for fueling and emission control. By comparing the information from the sensors to the to the data in the maps, the ECM (engine control module) is able to calculate the various output requirements. The ECM (engine control module) contains an adaptive strategy which updates the system when components vary due to production tolerances or ageing.

The ECM (engine control module) receives a vehicle speed signal on a CAN (controller area network) bus connection from the ABS (anti-lock brake system) Control Module. Vehicle speed is an important input to the ECM (engine control module) strategies. The ABS (anti-lock brake system) control module derives the speed signal from the ABS (anti-lock brake system) wheel speed sensors. The frequency of this signal changes according to road speed. The ECM (engine control module) uses this signal to determine the following:

ECM (engine control module) Harness Connector C0872 Pin details

Pin No Description Input/Output
A1 Serial to immobilization control module Output
A2 Serial from immobilization control module Input
A3 CAN (controller area network) Low Input/Output
A4 CAN (controller area network) High Input/Output
B1 Starter motor enable Output
B2 APP (accelerator pedal position) sensor ground -
B3 Radiator outlet temperature sensor ground -
B4 Speed control Input
C1 APP (accelerator pedal position) 1 Sensor ground -
C2 APP (accelerator pedal position) sensor 2 reference voltage Output
C3 ECT (engine coolant temperature) sensor 2 Output
C4 Speed control Input
D1 APP (accelerator pedal position) 1 signal Input
D2 APP (accelerator pedal position) 2 Sensor ground -
D3 Voltage 2 Input
D4 Not used -
E1 APP (accelerator pedal position) sensor 1 reference voltage Output
E2 Water in fuel sensor Input
E3 Stop switch 1 Input
E4 Inertia switch Input
F1 Intake air temperature sensor Input
F2 Not used -
F3 Engine cranking signal Input
F4 Mass air flow sensor Input
G1 Fuel pump power monitor Input
G2 Stop light switch Input
G3 Not used -
G4 Not used -
H1 Not used -
H2 Not used -
H3 Not used -
H4 Not used -
J1 Not used -
J2 E box fan Output
J3 Main relay Output
J4 Fuel pump relay Output
K1 Not used -
K2 Electric cooling fan control Output
K3 Ignition switch sense Input
K4 Keep alive power supply Input
L1 Battery voltage Input
L2 Battery voltage Input
L3 Battery voltage Input
L4 Ground -
M1 Ground -
M2 Ground -
M3 Ground -
M4 Ground -

ECM (engine control module) Harness Connector C0411 Pin details

Pin No Description Input/Output
A1 Engine oil temperature sensor Input
A2 Not used -
A3 Not used -
A4 Not used -
B1 Spare analogue input Input
B2 Spare analogue input Output
B3 CAN (controller area network) loop Low Input/Output
B4 CAN (controller area network) loop High Input/Output
C1 Not used Input
C2 Sensor ground  
C3 Not used  
C4 Knock sensor B - Input
D1 Fuel rail pressure sensor signal Input
D2 Fuel rail pressure sensor Output
D3 Knock sensor B + Output
D4 Knock sensor A- Input
E1 Throttle valve position sensor Input
E2 Fuel rail pressure sensor ground -
E3 Glow plug power monitor bank A Input
E4 Knock sensor bank A+ Input
F1 Electric throttle voltage Output
F2 Electric throttle ground -
F3 Glow plug monitor bank B Input
F4 Spare PWM (pulse width modulation) output Output
G1 Active engine mount control 1 Output
G2 Active engine mount control 2 Output
G3 Glow plug relay control Output
G4 Not used -
H1 Alternator command Output
H2 Not used -
H3 Not used -
H4 Not used -
J1 Not used -
J2 E box fan  
J3 Main relay Output
J4 Fuel volume control valve Output
K1 Oil temperature sensor ground -
K2 Viscous cooling fan control Output
K3 Fuel pressure control valve Input
K4 Inlet port deactivation actuator Output
L1 Injector 1 command Output
L2 Injector 1 common -
L3 Injector 3 common -
L4   Output
M1 Injector 3 command Output
M2 Injector 5 command Output
M3 Injector 5 common -
M4 Ground 7 -

ECM (engine control module) Harness Connector C2518 Pin details

Pin No Description Input/Output
A1 Spare analogue input -
A2 EGR (exhaust gas recirculation) valve position sensor bank B Input
A3 EGR (exhaust gas recirculation) valve position sensor bank A Input/Output
A4 Not used Input/Output
B1 Air charge temperature sensor Input
B2 Fuel temperature sensor Input
B3 Not used -
B4 Not used -
C1 Manifold absolute pressure sensor Input
C2 Engine coolant temperature sensor -
C3 Analogue voltage 1 Input
C4 VGT bank A Input
D1 Manifold absolute pressure sensor supply Output
D2 Sensor ground M Output
D3 Not used  
D4 Not used  
E1 Engine cooling fan monitor Input
E2 Not used -
E3 Not used -
E4 Not used -
F1 Crankshaft position sensor Input
F2 Generator load monitor signal Input
F3 Not used -
F4 Not used -
G1 Crankshaft position sensor supply Output
G2 Crankshaft position sensor ground -
G3 Variable geometry turbine actuator ground -
G4 Camshaft sensor signal Input
H1 EGR (exhaust gas recirculation) bank A + Output
H2 EGR (exhaust gas recirculation) bank A - -
H3 Camshaft position sensor ground -
H4 Camshaft position sensor supply Output
J1 EGR (exhaust gas recirculation) bank B+ Output
J2 VGT Bank A+ Output
J3 Not used Output
J4 Throttle valve actuator + Output
K1 EGR (exhaust gas recirculation) Bank B- -
K2 VGT - -
K3 Not used Input
K4 Throttle valve actuator - -
L1 Not used -
L2 Injector 2 common -
L3 Injector 0 common -
L4 Injector 4 common -
M1 Power ground -
M2 Injector 2 command Output
M3 Injector 0 command Output
M4 Injector 4 command Output

IMMOBILIZATION

The IMMOBILIZATION control module receives information from related systems on the vehicle and passes a coded signal to the ECM (engine control module) to allow starting if all starting parameters have been met. The information is decoded by the ECM (engine control module) which will allow the engine to run if the information is correct.

The information is on a rolling code system and both the imobilization control module and the ECM (engine control module) will require synchronisation if either component is renewed.

The ECM (engine control module) also protects the starter motor from inadvertent operation. The IMMOBILIZATION control module receives an engine speed signal from the ECM (engine control module) via the instrument cluster. When the engine speed exceeds a predetermined value, the imobilization control module prevents operation of the starter motor via an integral starter disable relay.   Anti-Theft - Passive (419-01B Anti-Theft - Passive)


CAMSHAFT POSITION SENSOR (CMP)



The CMP (camshaft position) is located on the front face of the left hand cylinder head. The sensor tip protrudes through the face to pick up on the reluctor behind the camshaft pulley. The CMP (camshaft position) is a Hall effect type sensor

The ECM (engine control module) uses the CMP (camshaft position) sensor signal to determine if the piston in No. 1 cylinder is at injection TDC or exhaust TDC. Once this has been established, the ECM (engine control module) can then operate the correct injector to inject fuel into the cylinder when the piston is at injection TDC.

The CMP (camshaft position) sensor is a Hall effect sensor which used by the ECM (engine control module) at engine start-up to synchronize the ECM (engine control module) with the CKP (crankshaft position) sensor signal. The ECM (engine control module) does this by using the CMP (camshaft position) sensor signal to identify number one cylinder to ensure the correct injector timing. Once the ECM (engine control module) has established the injector timing, the CMP (camshaft position) sensor signal is no longer used.

The CMP (camshaft position) sensor receives a 5V supply from the ECM (engine control module) . Two further connections to the ECM (engine control module) provide ground and signal output.

If a fault occurs, an error is registered in the ECM (engine control module) . Two types of failure can occur; camshaft signal frequency too high or total failure of the camshaft signal. The error recorded by the ECM (engine control module) can also relate to a total failure of the crankshaft signal or crankshaft signal dynamically implausible. Both components should be checked to determine the cause of the fault.

If a fault occurs with the CMP (camshaft position) sensor when the engine is running, the engine will continue to run but the ECM (engine control module) will deactivate boost pressure control. Once the engine is switched off, the engine will crank but will not restart while the fault is present.

CRANKSHAFT POSITION SENSOR (CKP)



The CKP (crankshaft position) sensor is located at the rear of the engine block on the left hand side. The sensor tip is aligned with a magnetic trigger which is attached to the crankshaft. The reluctor is a press fit on the end of the crankshaft. The trigger wheel must be carefully aligned to the crankshaft to ensure correct timing. The sensor produces a square wave signal, the frequency of which is proportional to engine speed.

The ECM (engine control module) monitors the CKP (crankshaft position) sensor signal and can detect engine over-speed. The ECM (engine control module) counteracts engine over-speed by gradually fading out speed synchronized functions. The CKP (crankshaft position) is a Hall effect sensor. The sensor measures the magnetic field variation induced by the magnetized trigger wheel.

The trigger wheel has two missing teeth representing 6º of crankshaft rotation. The two missing teeth provide a reference point for the angular position of the crankshaft.

When the space with the two missing teeth pass the sensor tip, a gap in the signal is produced which the ECM (engine control module) uses to determine the crankshaft position. The air gap between the sensor tip and the ring is important to ensure correct signals are output to the ECM (engine control module) . The recommended air gap between the CKP (crankshaft position) and the trigger wheel is 0.4 mm- 1.5 mm.

The ECM (engine control module) uses the signal from the CKP (crankshaft position) sensor for the following functions:

MASS AIR FLOW/INTAKE AIR TEMPERATURE (MAF (mass air flow) /IAT (intake air temperature) ) SENSOR



The MAF (mass air flow) /IAT (intake air temperature) sensor is located on the inlet air duct directly after the air filter box. The sensor combines the two functions of a MAF (mass air flow) sensor and an IAT (intake air temperature) sensor in one unit. The sensor is housed in a plastic molding which is connected between the intake manifold and the air intake pipe.

The MAF (mass air flow) sensor works on the hot film principle. Two sensing elements are contained within a film. One element is maintained at ambient (air intake) temperature, e.g. 25°Celsius (77°F). The other element is heated to 200°Celsius (392°F) above the ambient temperature, e.g. 225°Celsius (437°F). Intake air entering the engine passes through the MAF (mass air flow) sensor and has a cooling effect on the film. The ECM (engine control module) monitors the current required to maintain the 200°Celsius (392°F) differential between the two elements and uses the differential to provide a precise, non-linear, signal which equates to the volume of air being drawn into the engine.

The MAF (mass air flow) sensor output is a digital signal proportional to the mass of the incoming air. The ECM (engine control module) uses this data, in conjunction with signals from other sensors and information from stored fueling maps, to determine the precise fuel quantity to be injected into the cylinders. The signal is also used as a feedback signal for the EGR (exhaust gas recirculation) system.

The IAT (intake air temperature) sensor incorporates a NTC (negative temperature coefficient) thermistor in a voltage divider circuit. The NTC (negative temperature coefficient) thermistor works on the principle of decreasing resistance in the sensor as the temperature of the intake air increases. As the thermistor allows more current to pass to ground, the voltage sensed by the ECM (engine control module) decreases. The change in voltage is proportional to the temperature change of the intake air. Using the voltage output from the IAT (intake air temperature) sensor, the ECM (engine control module) can correct the fueling map for intake air temperature. The correction is an important requirement because hot air contains less oxygen than cold air for any given volume.

The MAF (mass air flow) sensor receives a 12V supply from the BJB (battery junction box) and a ground connection via the ECM (engine control module) . Two further connections to the ECM (engine control module) provide a MAF (mass air flow) signal and IAT (intake air temperature) signal.

The IAT (intake air temperature) sensor receives a 5V reference voltage from the ECM (engine control module) and shares a ground with the MAF (mass air flow) sensor. The signal output from the IAT (intake air temperature) sensor is calculated by the ECM (engine control module) by monitoring changes in the supplied reference voltage to the IAT (intake air temperature) sensor voltage divider circuit.

The ECM (engine control module) checks the calculated air mass against the engine speed. If the calculated air mass is not plausible, the ECM (engine control module) uses a default air mass figure which is derived from the average engine speed compared to a stored characteristic map. The air mass value will be corrected using values for boost pressure, atmospheric pressure and air temperature.

If the MAF (mass air flow) sensor fails the ECM (engine control module) implements the default strategy based on engine speed. In the event of a MAF (mass air flow) sensor signal failure, any of the following symptoms may be observed:

If the IAT (intake air temperature) sensor fails the ECM (engine control module) uses a default intake air temperature of -5°Celsius (23°F). In the event of an IAT (intake air temperature) sensor failure, any of the following symptoms may be observed:

ENGINE COOLANT TEMPERATURE SENSOR



The engine coolant temperature sensor is located in the top hose at the coolant manifold junction. The ECT (engine coolant temperature) sensor provides the ECM (engine control module) and the instrument cluster with engine coolant temperature status.

The ECM (engine control module) uses the temperature information for the following functions:

The instrument cluster uses the temperature information for temperature gauge operation. The engine coolant temperature signal is also transmitted on the CAN (controller area network) bus by the instrument cluster for use by other systems.

The ECM (engine control module) ECT (engine coolant temperature) sensor circuit consists of an internal voltage divider circuit which incorporates an NTC (negative temperature coefficient) thermistor. As the coolant temperature rises the resistance through the sensor decreases and vice versa. The output from the sensor is the change in voltage as the thermistor allows more current to pass to earth relative to the temperature of the coolant.

The ECM (engine control module) compares the signal voltage to stored values and adjusts fuel delivery to ensure optimum driveability at all times. The engine will require more fuel when it is cold to overcome fuel condensing on the cold metal surfaces inside the combustion chamber. To achieve a richer air/fuel ratio, the ECM (engine control module) extends the injector opening time. As the engine warms up the air/fuel ratio is leaned off.

The input to the sensor is a 5V reference voltage supplied from the voltage divider circuit within the ECM (engine control module) . The ground from the sensor is also connected to the ECM (engine control module) which measures the returned current and calculates a resistance figure for the sensor which relates to the coolant temperature.

The following table shows engine coolant temperature values and the corresponding sensor resistance and voltage values.

Coolant Temperature Sensor Response

Temperature (Degrees Celsius) Resistance (Kohms) Voltage (Volts)
-40 925 4.54
-30 496 4.46
-20 277 4.34
-10 160 4.15
0 96 3.88
10 59 3.52
20 37 3.09
30 24 2.62
40 16 2.15
50 11 1.72
60 7.5 1.34
70 5.6 1.04
80 3.8 0.79
90 2.9 0.64
100 2.08 0.49
110 1.56 0.38
120 1.19 0.29
130 0.918 0.22
140 0.673 0.17
150 0.563 0.14

If the ECT (engine coolant temperature) sensor fails, the following symptoms may be observed:

In the event of ECT (engine coolant temperature) sensor signal failure, the ECM (engine control module) applies a default value of 80°Celsius (176°F) coolant temperature for fueling purposes. The ECM (engine control module) will also permanently operate the cooling fan at all times when the ignition is switched on, to protect the engine from overheating.

ENGINE OIL TEMPERATURE SENSOR



The oil temperature sensor is located in the engine sump. The temperature sensor is a NTC (negative temperature coefficient) type which operates in the -30 Degrees Celsius to +150 Degrees Celsius temperature range.

Oil Temperature Sensor Response

Temperature Degrees Celsius Resistance Ohms
60 620
90 255
120 117
150 60

FUEL RAIL TEMPERATURE SENSOR

The fuel rail temperature sensor is located on the LP return line.

The sensor is an NTC (negative temperature coefficient) sensor which is connected to the ECM (engine control module) by two wires. The ECM (engine control module) fuel temperature sensor circuit consists of an internal voltage divider circuit which incorporates an NTC (negative temperature coefficient) thermistor. As the fuel temperature rises the resistance through the sensor decreases. The output from the sensor is the change in voltage as the thermistor allows more current to pass to earth relative to the temperature of the fuel.

The ECM (engine control module) monitors the fuel temperature constantly. If the fuel temperature exceeds 85°Celsius (185°F), the ECM (engine control module) invokes an engine 'derate' strategy. This reduces the amount of fuel delivered to the injectors in order to allow the fuel to cool. When this occurs, the driver may notice a loss of performance.

Further fuel cooling is available by a bi-metallic valve diverting fuel through the fuel cooler when the fuel reaches a predetermined temperature. In hot climate markets, an electrically operated cooling fan is positioned in the air intake ducking to the fuel cooler. This is controlled by a thermostatic switch, which switches the fan on and off when the fuel reaches a predetermined temperature.

The wires to the fuel sensor are monitored by the ECM (engine control module) for short and open circuit. The ECM (engine control module) also monitors the 5V supply. If a failure occurs a fault is recorded in the ECM (engine control module) memory and the ECM (engine control module) uses a default fuel pressure value.

If the ECM (engine control module) registers an 'out of range' deviation between the pressure signal from the sensor and the pre-programmed 'set point' a fault is stored in the ECM (engine control module) memory. Depending on the extent of the deviation, the ECM (engine control module) will reduce the injection quantity, stop the engine immediately or prevent further engine starting.

BRAKE LAMP SWITCH



The brake lamp switch is located on the brake box and is operated by the brake pedal. The switch has a normally open circuit switch which closes the circuit when the driver has applied the brakes. The switch is connected directly to the ECM (engine control module) and the ECM (engine control module) also receives a brake lamp signal on the CAN (controller area network) bus from the ABS (anti-lock brake system) module.

The ECM (engine control module) uses the brake signal for the following:

In the event of a brake switch failure, the following symptoms may be observed:

GLOW PLUGS



Three glow plugs are located in each of the cylinder heads, on the inlet side. The glow plugs and the glow plug relay are a vital part of the engine starting strategy. The glow plugs heat the air inside the cylinder during cold starts to assist combustion. The use of glow plugs helps reduce the amount of additional fuel required on start-up, and consequently reduces the emission of black smoke. The use of glow plugs also reduces the amount of injection advance required, which reduces engine noise, particularly when idling with a cold engine.

There are three phases of glow plug activity:

The main part of the glow plug is a tubular heating element which protrudes into the combustion chamber of the engine. The heating element contains a spiral filament encased in magnesium oxide powder. At the tip of the tubular heating element is the heater coil. Behind the heater coil, and connected in series, is a control coil. The control coil regulates the heater coil to ensure that it does not overheat.

Pre-heat is the length of time the glow plugs operate prior to engine cranking. The ECM (engine control module) controls the pre-heat time based on ECT (engine coolant temperature) sensor output and battery voltage. If the ECT (engine coolant temperature) sensor fails, the ECM (engine control module) will use the IAT (intake air temperature) sensor value as a default value. The pre-heat duration is extended if the coolant temperature is low and the battery is not fully charged.

Post heat is the length of time the glow plugs operate after the engine starts. The ECM (engine control module) controls the post heating time based on ECT (engine coolant temperature) sensor output. The post heat phase reduces engine noise, improves idle quality and reduces hydrocarbon emissions.

When the ignition is switched on to position II, the glow plug warning lamp illuminates and the instrument cluster displays 'PREHEATING' in the message center. The glow-lamp is activated separately from the glow-plugs, so is not illuminated during or after start. The plugs can still be ON when the lamp is off in these two phases.

In the event of glow plug failure, the engine may be difficult to start and excessive smoke emissions may be observed after starting.

The glow plug warning lamp also serves a second function within the EDC system. If a major EDC system fault occurs, the glow plug warning lamp will be illuminated permanently and a message generated in the instrument cluster. The driver must seek attention to the engine management system at a Land Rover dealer as soon as possible.

INTAKE AIR TEMPERATURE (BOOST AIR TEMPERATURE) SENSOR



The IAT (intake air temperature) is located in the rear of the intake chamber immediately preceding the electric throttle. The sensor is used to measure the intake air temperature from the turbo in order to calculate the required amount of fueling.

BOOST PRESSURE CONTROL

The Boost Pressure (BP) sensor is located post turbo after the eclectic throttle valve. The sensor provides a voltage signal to the ECM (engine control module) relative to the intake manifold pressure. The BP sensor has a three pin connector which is connected to the ECM (engine control module) and provides a 5V reference supply from the ECM (engine control module) , a signal input to the ECM (engine control module) and a ground for the sensor.

The BP sensor uses diaphragm transducer to measure pressure. The ECM (engine control module) uses the BP sensor signal for the following functions:

If the BP sensor fails, the ECM (engine control module) uses a default pressure of 1013 mbar (14 lbf/in²). In the event of a BP sensor failure, the following symptoms may be observed:

Boost control is achieved by the use of a direct drive electric actuator. The actuator is attached to the side of the turbo unit and is connected with the control mechanism via a linkage. The electric actuator works on the torque motor principal and has integrated control module.

The electric actuator moves the control vanes through an 60 degree stroke and has the capability to learn its own maximum stroke positions. The electric actuator is controlled via PWM (pulse width modulation) signals from the ECM (engine control module) .   Turbocharger (303-04D Fuel Charging and Controls - Turbocharger - 2.7L Diesel)


FUEL RAIL PRESSURE CONTROL VALVE



1  - Fuel volume control valve
2  - High pressure fuel pump
3  - Fuel rail pressure control valve

The fuel rail pressure control valve is incorporated into the high pressure fuel pump. The control valve regulates the fuel pressure within the fuel rail and is controlled by the ECM (engine control module) . The control valve is a PWM (pulse width modulation) controlled solenoid valve.

When the solenoid is de-energized, an internal spring holds an internal valve closed. At fuel pressure of 100 bar (1450 lbf/in²) or higher, the force of the spring is overcome, opening the valve and allowing fuel pressure to decay into the fuel return pipe. When the pressure in the fuel rail decays to approximately 100 bar (1450 lbf/in²) or less, the spring force overcomes the fuel pressure and closes the valve. When the ECM (engine control module) energizes the solenoid, the valve is closed allowing the fuel pressure to build. The pressure in the fuel rail in this condition can reach approximately 1300 bar (18854 lbf/in²).

The ECM (engine control module) controls the fuel rail pressure by operating the control valve solenoid using a PWM (pulse width modulation) signal. By varying the duty cycle of the PWM (pulse width modulation) signal, the ECM (engine control module) can accurately control the fuel rail pressure and hence the pressure delivered to the injectors according to engine load. This is achieved by the control valve allowing a greater or lesser volume of fuel to pass from the high pressure side of the pump to the un-pressurized fuel return line, regulating the pressure on the high pressure side.

The fuel rail pressure control valve receives a PWM (pulse width modulation) signal from the ECM (engine control module) of between 0 and 12V. The ECM (engine control module) controls the operation of the control valve using the following information to determine the required fuel pressure:

In the event of a total failure of the fuel rail pressure control valve, the engine will not start.

In the event of a partial failure of the fuel rail pressure control valve, the ECM (engine control module) will activate the solenoid with the minimum duty cycle which results in the injection quantity being limited.

FUEL VOLUME CONTROL VALVE

The fuel rail volume control valve is incorporated into the high pressure fuel pump. The VCV spills unwanted fuel back to the tank (or LP system) or forwards it to the PCV. This avoids unused fuel being pressurized by the HP stage of the pump, only to be spilt back to LP by the PCV wasting energy and heating the fuel.

INJECTORS

There are six electronic fuel injectors (one for each cylinder) located in a central position between the four valves of each cylinder. The ECM (engine control module) divides the injectors into two banks of three with cylinders 1 to 3 being designated bank A and cylinders 4 to 6 designated bank B, with injector numbers 1 and 4 at the front of the engine. Although the injectors are numbered 1-6 the firing order determined by the ECM (engine control module) software is numbered 0-5.

Injector/Cylinder Numbering

Injector Cylinder No
0 1
1 4
2 2
3 5
4 3
5 6

Each injector is supplied with pressurized fuel from the fuel rail and delivers finely atomized fuel directly into the combustion chambers. Each injector is individually controlled by the ECM (engine control module) which operates each injector in the firing order and controls the injector opening period via PWM (pulse width modulation) signals. Each injector receives a 12V supply from the ECM (engine control module) and, using programmed injection/timing maps and sensor signals, determines the precise pilot and main injector timing for each cylinder. If battery voltage falls to between 6 and 9V, fuel injector operation is restricted, affecting emissions, engine speed range and idle speed. In the event of a failure of a fuel injector, the following symptoms may be observed:

The ECM (engine control module) monitors the wires for each injector for short circuit and open circuit, each injector and the transient current within the ECM (engine control module) . If a defect is found, an error is registered in the ECM (engine control module) for the injector in question.   Fuel Charging and Controls (303-04C Fuel Charging and Controls - 2.7L Diesel)


EGR SYSTEM

The EGR (exhaust gas recirculation) system comprises:

EGR (exhaust gas recirculation)



The EGR (exhaust gas recirculation) modulator and cooler are a combined unit.

The combined EGR (exhaust gas recirculation) modulator and cooler is located under each cylinder bank, between the exhaust manifold and the cylinder head. The cooler side of the EGR (exhaust gas recirculation) is connected to the vehicle cooling system, via hoses. The inlet exhaust side is connected directly into the exhaust manifolds on each side. The exhaust gas passes through the cooler and is expelled via the actuator and a metal pipe into the throttle housing. The EGR (exhaust gas recirculation) modulator is a solenoid operated valve which is controlled by the ECM (engine control module) . The ECM (engine control module) uses the EGR (exhaust gas recirculation) modulator to control the amount of exhaust gas being re-circulated in order to reduce exhaust emissions and combustion noise. The EGR (exhaust gas recirculation) is enabled when the engine is at normal operating temperature and under cruising conditions.

The EGR (exhaust gas recirculation) modulator receives a 12V supply from the ECM (engine control module) and is controlled using a PWM (pulse width modulation) signal. The PWM (pulse width modulation) duty signal of the solenoid ground is varied to determine the precise amount of exhaust gas delivered to the cylinders.

The modulators are operated through their full range at each engine shut down, to clear any carbon deposits that may have built up whilst the engine was running

In the event of a failure of the EGR (exhaust gas recirculation) modulator, the EGR (exhaust gas recirculation) function will become inoperative. The ECM (engine control module) can monitor the EGR (exhaust gas recirculation) modulator solenoid for short circuits and store fault codes in the event of failure. The modulator can also be activated for testing using a Land Rover approved diagnostic system.

ACCELERATOR PEDAL POSITION (APP) SENSOR



The APP (accelerator pedal position) sensor is incorporated into the pedal assembly. The sensor is a twin track rotary potentiometer type.

The APP (accelerator pedal position) sensor is located in plastic housing which is integral with the throttle pedal. The housing is injection molded and provides location for the APP (accelerator pedal position) sensor. The sensor is mounted externally on the housing and is secured with two Torx screws. The external body of the sensor has a six pin connector which accepts a connector on the vehicle wiring harness.

The sensor has a spigot which protrudes into the housing and provides the pivot point for the pedal mechanism. The spigot has a slot which allows for a pin, which is attached to the sensor potentiometers, to rotate through approximately 90°, which relates to pedal movement. The pedal is connected via a link to a drum, which engages with the sensor pin, changing the linear movement of the pedal into rotary movement of the drum. The drum has two steel cables attached to it. The cables are secured to two tension springs which are secured in the opposite end of the housing. The springs provide 'feel' on the pedal movement and require an effort from the driver similar to that of a cable controlled throttle. A detente mechanism is located at the forward end of the housing and is operated by a ball located on the drum. At near maximum throttle pedal movement, the ball contacts the detente mechanism. A spring in the mechanism is compressed and gives the driver the feeling of depressing a 'kickdown' switch when full pedal travel is achieved.

ELECTRONIC THROTTLE



The electric throttle body is located in the inlet tract prior to where the inlet splits to divert air flow into the two separate air intake manifolds. The electric throttle controls the volume of air allowed into the inlet manifold by means of a DC motor which controls a flap in the body of the throttle. This is done in response to inputs from the engine management system.

Just after the throttle flap the tubes from the EGR (exhaust gas recirculation) valves/coolers are joined into the assembly.

DIESEL PARTICULATE FILTER (DPF) CONTROL - VEHICLES FROM 2008MY

Vehicles from 2008MY are fitted with a Diesel Particulate Filter (DPF) which collects the particulate matter produced during the combustion process and reduces the particulates entering the atmosphere.

The DPF is located in the exhaust system, downstream of the catalytic converter. A major feature of the DPF is its ability for regeneration. Regeneration is the burning of particulates trapped by the filter to prevent obstruction to the free flow of exhaust gasses. The regeneration process is controlled by the ECM and takes place at calculated intervals and is not noticeable by the driver of the vehicle.

For details of the DPF and the regeneration processes refer to the relevant exhaust system section.   Exhaust System (309-00C )


Regeneration is most important, since an overfilled filter can damage the engine through excessive exhaust back pressure and can itself be damaged or destroyed.

The exhaust gas and DPF temperatures are controlled by the DPF software located in the ECM. The DPF software monitors the load status of the DPF based on driving style, distance travelled and signals from a differential pressure sensor and temperature sensors located before and after the DPF in the exhaust system. When the particulate loading of the DPF reaches predetermined levels, the DPF is actively regenerated by adjusting, in conjunction with the ECM, various engine control functions such as:

The regeneration process is possible because of the flexibility of the common-rail fuel injection engine which provides precise control of fuel flow, fuel pressure and injection timing which are essential requirements to promote the efficient regeneration process.

The ECM contains the DPF software which controls and monitors the DPF and the regeneration process. The software is broken down into three separate modules; a DPF supervisor module, a DPF fuel management module and a DPF air management module, which interact with each other to provide precise DPF control.

These three modules are controlled by a fourth software module known as the DPF co-ordinator module. The co-ordinator module manages the operation of the other modules when an active regeneration is requested. The DPF supervisor module is a sub-system of the DPF co-ordinator module.

DPF Co-Ordinator Module

The DPF co-ordinator module reacts to a regeneration request from the supervisor module by initiating and controlling the following DPF regeneration requests: When the supervisor module issues a regeneration request, the co-ordinator module requests EGR cut-off and a regeneration specific turbocharger boost pressure control. It then waits for a feedback signal from the EGR system confirming that the EGR valve is closed.

:
  The EGR valve is open at idle to allow reduced NO. EGR is not used during part load due to intake manifold contamination.

When the EGR valve is closed, the co-ordinator module initiates requests to increase engine load by controlling the intake air temperature and pressure.

Once confirmation is received that intake conditions are controlled or a calibration time has expired, the co-ordinator module then changes to a state awaiting an accelerator pedal release manoeuvre from the driver. If this occurs or a calibration time has expired, the co-ordinator module generates a request to control fuel injections to increase exhaust gas temperature.

DPF Fuel Management Module

The DPF fuel management module controls the following functions:

The above functions are dependant on the condition of the catalytic converter and the DPF.

The controlled injection determines the required injection level in addition to measuring the activity of the catalytic converter and the DPF. The fuel management calculates the quantity and timing for the four split injections, for each of the three calibration levels for injection pressure, and also manages the transition between the levels.

The two post injections are required to separate the functionality of increasing in-cylinder gas temperatures and the production of hydrocarbons. The first post injection is used to generate the higher in-cylinder gas temperature while simultaneously retaining the same engine torque output produced during normal (non-regeneration) engine operation. The second post injection is used to generate hydrocarbons by allowing unburnt fuel into the catalytic converter without producing increased engine torque.

DPF Air Management Module

The DPF air management module controls the following functions: During active regeneration, the EGR operation is disabled and the closed-loop activation of the turbocharger boost controller is calculated. The air management module controls the air in the intake manifold to a predetermined level of pressure and temperature. This control is required to achieve the correct in-cylinder conditions for stable and robust combustion of the post injected fuel.

Restricting the air intake during DPF regeneration has the following functions:

The module controls the intake air temperature by actuating the EGR throttle and by adjustment of the turbocharger boost pressure control.

DPF Temperature Sensors



Three temperature sensors are used in the DPF system. One is located in the turbocharger outlet elbow, the second sensor is after the catalytic converter and the third sensor is located after the DPF.

The sensors measure the temperature of exhaust gas exiting the turbocharger, before it passes through the DPF and after it has passed through the DPF and provides the information required by the ECM to calculate the DPF temperature. The information is used, in conjunction with other data, to estimate the amount of accumulated particulate and to control the DPF temperature.

The sensors are Negative Temperature Co-efficient (NTC) type resistors, which measure the temperature of the exhaust gases. The resistance, and subsequently the voltage at the sensor, will decrease as the exhaust gas temperature increases.

In the event of a fault in a temperature sensor, the ECM uses a substitute value of 350°C (1202°F).

Differential Pressure Sensor



1   Low pressure connection
2   High pressure connection
3   Electrical connector

The differential pressure sensor is located on the rear of the transfer box, adjacent to the DPF.

The differential pressure sensor is used by the DPF software to monitor the condition of the DPF. Two pipe connections on the sensor are connected by pipes to the inlet and outlet ends of the DPF. The pipes allow the sensor to measure the inlet and outlet pressures of the DPF.

As the amount of particulates trapped by the DPF increases, the pressure at the inlet side of the DPF increases in comparison to the DPF outlet. The DPF software uses this comparison, in conduction with other data, to calculate the accumulated amount of trapped particulates.

By measuring the pressure difference between the DPF inlet and outlet air flow and the DPF temperature, the DPF software can determine if the DPF is becoming blocked and requires regeneration.

A DPF is recognized as overloaded if the differential pressure under certain operating conditions exceeds the overload limit calculated by the ECM. The DPF software may start regeneration attempts but be unable to complete them. These attempts are counted by the ECM and, if the maximum number of regeneration attempts is reached, a fault entry is recorded in the ECM at the next ignition on cycle.

The DPF software performs the following checks using the DPF differential pressure sensor:

TERRAIN RESPONSE™

Terrain Response system allows the driver to select a program which will provide the optimum settings for traction and performance for prevailing terrain conditions.

As part of Terrain Response there will be different throttle pedal progression maps associated with different Terrain Response modes. The two extremes are likely to be a sand map (quick build up of torque with pedal travel) and grass/gravel/snow (very cautious build up of torque).

The TdV6 implementation of throttle progression is based on a fixed blend time. The torque will blend from that on one map to that on the new map (for the same pedal position) over a fixed time. This means blending will always take the same amount of time but when the torque change is small the torque increase over time will be small, whilst if the torque change is greater then the torque increase over time will be steeper. The resulting acceleration of the vehicle will depend on the torque difference between the two maps as well as on the gear and range selected. The worst case blending that could ever occur has been calibrated to match the blend rate for petrol derivatives as closely as possible, so as to give a transparent behavior to customers.   Ride and Handling Optimization (204-06 Ride and Handling Optimization)


CENTRAL JUNCTION BOX



The CJB (central junction box) initiates the power up and power down routines within the ECM (engine control module) . When the ignition is turned on 12V is applied to the Ignition Sense input. The ECM (engine control module) then starts its power up routines and turns on the ECM (engine control module) main relay; the main power to the ECM (engine control module) and it's associated system components. When the ignition is turned OFF the ECM (engine control module) will maintain its powered up state for up to 20 seconds while it initiates its power down routine and on completion will turn off the ECM (engine control module) main relay.

GENERATOR



The generator has a multifunction voltage regulator for use in a 14V charging system with 6÷12 zener diode bridge rectifiers.

The ECM (engine control module) monitors the load on the electrical system via PWM (pulse width modulation) signal and adjusts the generator output to match the required load. The ECM (engine control module) also monitors the battery temperature to determine the generator regulator set point. This characteristic is necessary to protect the battery; at low temperatures battery charge acceptance is very poor so the voltage needs to be high to maximize any rechargeability, but at high temperatures the charge voltage must be restricted to prevent excessive gassing of the battery with consequent water loss.   Generator (414-02C Generator and Regulator - 2.7L Diesel)


The generator has a smart charge capability that will reduce the electrical load on the generator reducing torque requirements, this is implemented to utilize the engine torque for other purposes. This is achieved by monitoring three signals to the ECM (engine control module) :