2010 JAGUAR XFR Ejb relay

14 Radiator 15 Auxiliary radiator 16 Connection with supercharger cooling system
System Operation
When the engine is running, the coolant is circulated around the engine cooling system by the coolant pump. From the coolant
pump, coolant flows through the cylinder heads and the engine oil cooler into the cylinder block and the heater manifold.

In the cylinder block, the coolant flows forwards to the outlet tube. When the coolant is cold, the thermostat is closed and the
coolant flows direct from the outlet tube back to the coolant pump. Once the coolant reaches operating temperature the
thermostat begins to open, to control system temperature, and coolant flows from the outlet tube to the coolant pump via the
radiator and, on SC (supercharger) vehicles, the auxiliary radiator. When the thermostat is open, the coolant flow through the
radiator(s) also generates a coolant flow through the transmission fluid cooler.

From the heater manifold the coolant flows through the electronic throttle and the heater core, in parallel circuits that are
unaffected by the position of the thermostat. From the electronic throttle, the coolant merges with bleed coolant from the
coolant pump and the outlet tube and flows to the expansion tank. From the heater core, the coolant flows back to the inlet of
the coolant pump.

Expansion and contraction of the coolant is accommodated by an air space in the expansion tank and the compliance of the
flexible hoses.

If the coolant level in the expansion tank decreases below a predetermined value, the level sensor connects a ground to the
instrument cluster, which activates the appropriate warning. For additional information, refer to 413-01 Instrument Cluster.

The cooling fan is operated by a fan control module integrated into the cooling fan motor. The fan control module regulates the
voltage, and thus speed, of the cooling fan motor in response to a PWM (pulse width modulation) signal from the ECM (engine
control module).

The cooling fan receives a battery feed and an ignition feed from the EJB (engine junction box). The ignition feed is supplied
from the main relay in the EJB, which is controlled by the ECM.
The ECM calculates the required fan speed from the engine temperature, A/C (air conditioning) system pressure and transmission fluid temperature. Under hot operating conditions, the fan may continue to operate for 4 minutes after the engine
has been switched off.



COOLANT PUMP Component Description



Item Description 1 Inlet connection 2 Pump body 3 Outlet flange to RH cylinder head 4 Outlet to engine oil cooler 5 Outlet flange to LH cylinder head

Published: 11-May-2011
Starting System - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Starting System - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired



Item Description 1 Battery 2 Starter motor 3 EJB (starter relay) 4 ECM 5 BJB (250 A megafuse) 6 BJB (400 A megafuse)

When the ECM receives a crank request, it energizes the starter relay in the EJB (engine junction box). The energized starter relay supplies 12 V power (fed via the 250 A megafuse in the BJB (battery junction box)) to energize the pull-in coil of the
starter solenoid. Once activated, the pull-in coil engages the solenoid plunger, which engages the pinion with the ring gear.
The plunger then closes the solenoid circuit, feeding power from the 400 A megafuse in the BJB to the starter motor.

Published: 11-May-2011
Engine Ignition - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Engine Ignition - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired



Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 EJB (engine junction box (ignition relay)) 4 CJB (central junction box) 5 RFI suppressor 6 LH (left hand) cylinder bank ignition coil (4 off) 7 RH (right hand) cylinder bank ignition coil (4 off) 8 ECM

GENERAL System Operation

The ignition coils are supplied with electrical power from the battery via a 250 A megafuse in the BJB (battery junction box)
and the ignition relay in the EJB (engine junction box). The control signal for the ignition relay is supplied by the CJB (central
junction box).

The ECM (engine control module) sends a separate signal to each ignition coil to trigger the power stage switching. The ECM calculates the dwell time from the battery voltage and engine speed, to ensure a constant energy level is produced in the
secondary coil each time the power stage is switched. This ensures sufficient spark energy is available without excessive
primary current flow, which avoids overheating and damage to the ignition coils.
The ECM calculates the ignition timing for individual cylinders from: Engine speed
Camshaft position
Engine load
Engine temperature
The knock control function
The shift control function
The idle speed control function.



IGNITION COILS Component Description



The ignition coils are installed in the cylinder head covers, under the NVH (noise, vibration and harshness) covers. Each
ignition coil locates on a spark plug and is secured to the related cylinder head cover with a single screw. Each ignition coil
incorporates a three pin electrical connector for connection to the engine harness.

Each ignition coil contains a primary and a secondary winding. The primary winding receives electrical power from the ignition
relay in the power distribution box. A power stage in the primary winding allows the ECM to interrupt the power supply, to induce a voltage in the secondary winding and thus the spark plug. A diode in the ground side of the secondary winding
reduces any undesirable switch-on voltage, to prevent misfiring into the intake manifold. The power stage limits the maximum
voltage and current in the primary winding, to protect the power stage and limit the voltage in the secondary winding. www.JagDocs.com

Published: 11-May-2011
Intake Air Distribution and Filtering - V8 S/C 5.0L Petrol - Intake Air
Distribution and Filtering - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired



Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 EJB (engine junction box) (EMS high current relay) 4 Tuning valve 5 ECM (engine control module)

rear window heater switch is pressed or the engine stops.

Automatic operation during a journey is initiated when low ambient air temperatures are experienced and the vehicle has been
travelling for a set period of time above a threshold speed. In this instance, no feedback is given to the driver to inform him
the rear window heater is operational (the switch LED is not illuminated). The duration of heater operation is variable depending on the ambient air temperature, vehicle speed and the amount of time the vehicle has been travelling.

Windshield Heater (Where Fitted)

Windshield heater operation is only enabled when the engine is running. The ATC module controls operation of the windshield heater using two relays in the EJB (engine junction box). When windshield heater operation is required, the ATC module broadcasts a message to the CJB on the medium speed CAN bus. On receipt of the message, the CJB energizes the relays by providing a ground path for both relay coils. This allows a battery feed to flow across the relays to power the windshield left
and right heater elements.
There are two modes of windshield heater operation; manual and automatic.

Manual operation is activated by pressing the windshield heater switch on the integrated control panel. When the switch is
pressed, the status LED in the switch illuminates and the windshield heater elements are energized. Manual operation is discontinued when the windshield heater switch is pressed a second time, 5 minutes have elapsed (the heating phase), or the
engine stops. If manual operation is discontinued by the engine stopping, the previous heating phase is resumed if the engine
is re-started within 30 seconds.

There are two variants of automatic operation; automatic operation at the start of a journey and automatic operation during a
journey.

Automatic operation at the start of a journey is initiated if the ambient air temperature is below 5 °C (41 °F). In this instance,
the switch LED is illuminated and the heater elements are energized for 6.5 minutes. Automatic operation is discontinued if the windshield heater switch is pressed or the engine stops.

Automatic operation during a journey is initiated when low ambient air temperatures are experienced and the vehicle has been
travelling for a set period of time above a threshold speed. In this instance, no feedback is given to the driver to inform him
the windshield heater is operational (the switch LED is not illuminated) and the duration of operation is variable depending upon the ambient air temperature, vehicle speed and the amount of time the vehicle has been travelling.

Exterior Mirror Heaters

Operation of the exterior mirror heaters is fully automatic and not controllable by the driver. Exterior mirror heater operation is
determined by ambient air temperature and windshield wiper status. When ambient air temperature reaches a pre-determined
level, the ATC module broadcasts an exterior mirror heating request to the door modules over the medium speed CAN bus. On receipt of this message, the door modules provide feed and ground connections to both exterior mirror heater elements.

The amount of time the exterior mirror heaters are operational increases if the windshield wipers are switched on. This ensures
the mirrors remain mist free in damp and wet conditions, where there is an increased risk of misting.

Seat Heaters (Where Fitted)

There are four seat heater settings available; off, 1, 2 and 3, which can be selected on the home and climate control screens
of the TSD. The heat setting is relayed to the vehicle occupants through a graduated display on the TSD.

Operation of the heated seats is controlled by the ATC module. When the ATC module receives a heating request from the TSD, it broadcasts a message to the CJB over the medium speed CAN bus. The CJB then provides a hardwired 12 V supply to the three heater elements in the related front seat. The heater elements, two in the seat cushion and one in the seat squab,
are wired in series. The ATC module monitors seat temperature using a temperature sensor located in each seat cushion. The CJB provides the temperature sensors with a 5 V supply. The level of the returned voltage back to the CJB is proportional to the seat temperature. The value of the return signal is broadcast to the ATC module, over the medium speed CAN bus, which allows it to control the seat temperature to the required level. The ATC module will suspend or disable operation of the seat heaters if any of the following occur:

Battery voltage exceeds 16.5 ± 0.3 V for more than 5 seconds. Seat heating is re-enabled when battery voltage
decreases to 16.2 ± 0.3 V.
If a short or open circuit is detected.
If the seat heat temperature rises significantly above the target temperature setting.

The graduated display on the TSD remains illuminated until the seat heaters are turned off or the engine stops. If the engine
is restarted within 30 seconds the seat heater resumes the previous heating level.

1 CJB Generator 2 BJB Starter motor 3 GWM (gateway module) 4 DBM (dual battery module) 5 RJB Duel battery module 6 Battery to BJB terminal 7 BMS (battery monitoring system) Duel battery fuse box 8 Primary battery 9 Transit relay 10 Secondary battery 11 DBJB (dual battery junction box) 12 ECM 13 Generator 14 EJB COMPONENT LOCATION - DUAL BATTERY VEHICLES
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