2010 JAGUAR XFR fuse box

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

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)

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

Control Diagram

NOTE: A = Hardwired; D = High speed CAN (controller area network) bus.
CONTROL DIAGRAM SHEET 1 OF 2



Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 EJB (engine junction box) 4 ECM

Published: 11-May-2011
Automatic Transmission/Transaxle - TDV6 3.0L Diesel /V8 5.0L Petrol/V8 S/C 5.0L Petrol - Transmission Description - System Operation and Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; B = K bus; D = High speed CAN (controller area network) bus; O = LIN (local interconnect
network) bus



Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 EJB (engine junction box) 4 CJB (central junction box)

Published: 11-May-2011
Automatic Transmission/Transaxle External Controls - TDV6 3.0L Diesel /V8 5.0L Petrol/V8 S/C 5.0L Petrol - External Controls - System Operation and
Component Description
Description and Operation

Control Diagram

NOTE: A = Hardwired; D = High speed CAN (controller area network) bus; O = LIN (local interconnect network) bus



Item Description 1 Battery 2 BJB (battery junction box) (250 A megafuse) 3 CJB (central junction box) 4 EJB (engine junction box) 5 TCM (transmission control module)