2010 JAGUAR XFR relay

1 RH (right hand) charge air cooler 2 Engine 3 LH (left hand) charge air cooler 4 Expansion hose connection (with engine cooling system) 5 Charge air radiator 6 Charge air coolant pump
System Operation
Electrical power for the charge air coolant pump is supplied from the intercooler water pump relay in the power distribution box.
When the intercooler water pump relay is energized, it connects power from the battery, via the BJB (battery junction box)
and CJB (central junction box), to the charge air coolant pump. Operation of the intercooler water pump relay is controlled by
the ECM (engine control module). The intercooler water pump relay is energized continuously while the ignition is in power
mode 6.

When the charge air coolant pump is running, coolant flows from the pump outlet through the charge air coolers, the charge air
radiator and back to the pump inlet. Supercharger Cooling Flow Diagram

Symptom Possible Causes Action Purge valve
Difficult hot start
Injector leak
Electronic engine control
Purge valve
Fuel pump
Ignition system
EGR valve stuck open Check for injector leak, install new injector as required.
Check for electronic engine controls, evaporative emissions,
fuel system, ignition system and engine emission system
related DTCs and refer to the relevant DTC Index Difficult to start after hot
soak (vehicle standing,
engine off, after engine has
reached operating
temperature)
Injector leak
Electronic engine control
Purge valve
Fuel pump
Ignition system
EGR valve stuck open Check for injector leak, install new injector as required.
Check for electronic engine controls, evaporative emissions,
fuel system, ignition system and engine emission system
related DTCs and refer to the relevant DTC Index Engine stalls soon after start
Breather system
disconnected/restricted
ECM relay
Electronic engine control
Ignition system
Air intake system restricted
Air leakage
Fuel lines Ensure the engine breather system is free from restriction
and is correctly installed. Check for electronic engine
control, ignition system and fuel system related DTCs and
refer to the relevant DTC Index. Check for blockage in air
filter element and air intake system. Check for air leakage
in air intake system Engine hesitates/poor
acceleration
Fuel pressure, fuel pump,
fuel lines
Injector leak
Air leakage
Electronic engine control
Throttle motor
Restricted accelerator pedal
travel (carpet, etc)
Ignition system
EGR valve stuck open
Transmission malfunction Check for fuel system related DTCs and refer to the
relevant DTC Index. Check for injector leak, install new
injector as required. Check for air leakage in air intake
system. Ensure accelerator pedal is free from restriction.
Check for electronic engine controls, ignition, engine
emission system and transmission related DTCs and refer
to the relevant DTC Index Engine backfires
Fuel pump/lines
Air leakage
Electronic engine controls
Ignition system
Sticking variable camshaft
timing (VCT) hub Check for fuel system failures. Check for air leakage in
intake air system. Check for electronic engine controls,
ignition system and VCT system related DTCs and refer to
the relevant DTC Index Engine surges
Fuel pump/lines
Electronic engine controls
Throttle motor
Ignition system Check for fuel system failures. Check for electronic engine
controls, throttle system and ignition system related DTCs
and refer to the relevant DTC Index Engine detonates/knocks
Fuel pump/lines
Air leakage
Electronic engine controls
Sticking VCT hub Check for fuel system failures. Check for air leakage in
intake air system. Check for electronic engine controls and
VCT system related DTCs and refer to the relevant DTC
Index No throttle response
Electronic engine controls
Throttle motor Check for electronic engine controls and throttle system
related DTCs and refer to the relevant DTC Index Poor throttle response
Breather system
disconnected/restricted
Electronic engine control
Transmission malfunction
Traction control event Air
leakage Ensure the engine breather system is free from restriction
and is correctly installed. Check for electronic engine
controls, transmission and traction control related DTCs and
refer to the related DTC Index. Check for air leakage in
intake air system DTC Index

For a list of Diagnostic Trouble Codes (DTCs) that could be logged in the Engine Control Module (ECM), please refer to Section
303-14.
REFER to: Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing) / Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing).

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
Starting System - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Starting System
Diagnosis and Testing

Principles of Operation

For a detailed description of the starting system and operation, refer to the relevant Description and Operation section of the
workshop manual. REFER to: (303-06C Starting System - V8 5.0L Petrol/V8 S/C 5.0L Petrol)

Starting System (Description and Operation), Starting System (Description and Operation), Starting System (Description and Operation).
Inspection and Verification


CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not
guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle.


NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection
Mechanical Electrical
Gear selector lever cable adjustment (vehicles with automatic
transmission)
Starter motor
Engine (turns freely)
Battery
Fuses
Starter relay
Wiring harness(es)
Damaged, loose or corroded
connectors
Ignition switch
Generator
Transmission Control Module (TCM)
Engine Control Module (ECM)
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step.

4. If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for
Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.

Symptom Chart

Symptom Possible Causes Action The engine does
not crank (starter
motor does not
turn)
Gear selector not in P or N
position (vehicles with
automatic transmission)
Battery
Starter relay
Invalid key code received by
Central Junction Box (CJB)
Harness/Connectors
Starter motor
Ignition switch
Generator
Transmission Control Module
(TCM)
Engine Control Module (ECM)
Engine seized Make sure the gear selector is in the P or N position and correctly
adjusted. Check the battery condition and state of charge. Check for
DTCs indicating an immobilizer fault. Check the starter motor relay,
ignition switch and generator circuits. Refer to the electrical guides.
Check for TCM and ECM DTCs. Check that the engine turns freely. The engine does
not crank (starter
motor does turn)
Starter motor installation
Starter motor
Flywheel/Drive plate ring
gear Check the starter motor installation (fasteners tight, starter motor
square to engine, etc). Check the flywheel/drive plate ring gear teeth
for damage, foreign objects, etc. www.JagDocs.com

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

Symptom Possible Causes Action Difficult hot start
Injector leak
Electronic engine control
Purge valve
Fuel pump
Ignition system
EGR valve stuck open Check for injector leak, install new injector as required.
Check for electronic engine controls, evaporative emissions,
fuel system, ignition system and engine emission system
related DTCs and refer to the relevant DTC Index Difficult to start after hot
soak (vehicle standing,
engine off, after engine has
reached operating
temperature)
Injector leak
Electronic engine control
Purge valve
Fuel pump
Ignition system
EGR valve stuck open Check for injector leak, install new injector as required.
Check for electronic engine controls, evaporative emissions,
fuel system, ignition system and engine emission system
related DTCs and refer to the relevant DTC Index Engine stalls soon after start
Breather system
disconnected/restricted
ECM relay
Electronic engine control
Ignition system
Air intake system restricted
Air leakage
Fuel lines Ensure the engine breather system is free from restriction
and is correctly installed. Check for electronic engine
control, ignition system and fuel system related DTCs and
refer to the relevant DTC Index. Check for blockage in air
filter element and air intake system. Check for air leakage
in air intake system Engine hesitates/poor
acceleration
Fuel pressure, fuel pump,
fuel lines
Injector leak
Air leakage
Electronic engine control
Throttle motor
Restricted accelerator pedal
travel (carpet, etc)
Ignition system
EGR valve stuck open
Transmission malfunction Check for fuel system related DTCs and refer to the
relevant DTC Index. Check for injector leak, install new
injector as required. Check for air leakage in air intake
system. Ensure accelerator pedal is free from restriction.
Check for electronic engine controls, ignition, engine
emission system and transmission related DTCs and refer
to the relevant DTC Index Engine backfires
Fuel pump/lines
Air leakage
Electronic engine controls
Ignition system
Sticking variable camshaft
timing (VCT) hub Check for fuel system failures. Check for air leakage in
intake air system. Check for electronic engine controls,
ignition system and VCT system related DTCs and refer to
the relevant DTC Index Engine surges
Fuel pump/lines
Electronic engine controls
Throttle motor
Ignition system Check for fuel system failures. Check for electronic engine
controls, throttle system and ignition system related DTCs
and refer to the relevant DTC Index Engine detonates/knocks
Fuel pump/lines
Air leakage
Electronic engine controls
Sticking VCT hub Check for fuel system failures. Check for air leakage in
intake air system. Check for electronic engine controls and
VCT system related DTCs and refer to the relevant DTC
Index No throttle response
Electronic engine controls
Throttle motor Check for electronic engine controls and throttle system
related DTCs and refer to the relevant DTC Index Poor throttle response
Breather system
disconnected/restricted
Electronic engine control
Transmission malfunction
Traction control event Air
leakage Ensure the engine breather system is free from restriction
and is correctly installed. Check for electronic engine
controls, transmission and traction control related DTCs and
refer to the related DTC Index. Check for air leakage in
intake air system DTC Index

For a list of Diagnostic Trouble Codes (DTCs) that could be logged in the Engine Control Module (ECM), please refer to Section
303-14. REFER to:

Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing), Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing).