2010 JAGUAR XFR spark plug

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

OVERVIEW

The engine ignition system is a coil-on-plug, single spark system controlled by the ECM (engine control module). An iridium
tipped spark plug is installed in each combustion chamber, between the inlet and exhaust valves, and an ignition coil is
installed on each spark plug. A RFI (radio frequency interference) suppressor is connected to the power feed to the ignition
coils.

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
Engine Ignition - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Engine Ignition
Diagnosis and Testing

Principles of Operation

For a detailed description of the engine ignition system and operation, refer to the relevant Description and Operation section
of the workshop manual. REFER to: (303-07B Engine Ignition - V8 5.0L Petrol/V8 S/C 5.0L Petrol)

Engine Ignition (Description and Operation), Engine Ignition (Description and Operation), Engine Ignition (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
Engine oil level
Cooling system coolant level
Fuel level
Fuel contamination/grade/quality
Exhaust gas recirculation (EGR) valves
Fuses
Wiring harness
Loose or corroded electrical connectors
Ignition coils
Sensor(s)
Engine Control Module (ECM)
Transmission Control Module (TCM)
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 Engine cranks, but does not
fire
Engine breather system
disconnected/restricted
Ignition system
Fuel system
Electronic engine control Ensure the engine breather system is free from restriction
and is correctly installed. Check for ignition system, fuel
system and electronic engine control DTCs and refer to the
relevant DTC Index Engine cranks and fires, but
will not start
Evaporative emissions purge
valve
Fuel pump
Spark plugs
HT short to ground (tracking)
check rubber boots for
cracks/damage
Ignition system Check for evaporative emissions, fuel system and ignition
system related DTCs and refer to the relevant DTC Index Difficult cold start
Engine coolant level/anti-
freeze content
Battery
Electronic engine controls
Exhaust Gas Recirculation
(EGR) valve stuck open
Fuel pump
Purge valve Check the engine coolant level and condition. Ensure the
battery is in a fully charged and serviceable condition.
Check for electronic engine controls, engine emissions, fuel
system and evaporative emissions system related DTCs
and refer to the relevant DTC Index

Published: 16-Sep-2013
Electronic Engine Controls - V8 S/C 5.0L Petrol - Electronic Engine Controls
Diagnosis and Testing

Principle of Operation

For a detailed description of electronic engine controls, refer to the relevant Description and Operation section of the workshop
manual. REFER to: (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol)

Electronic Engine Controls (Description and Operation), Electronic Engine Controls (Description and Operation), Electronic Engine Controls (Description and Operation).
Inspection and Verification

1. Verify the customer concern.

2. Visually inspect for obvious signs of damage and system integrity.

Visual Inspection
Mechanical Electrical
Engine oil level and condition
Cooling system coolant level
Fuel level
Fuel contamination/grade/quality
Throttle body
Front End Accessory Drive (FEAD) belt
Air cleaner condition
Fuses
Wiring harness
Electrical connector(s)
Sensor(s)
Engine Control Module
Transmission Control Module
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 customer concern and refer to the Symptom Chart below, alternatively,
check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.
Symptom Chart

Symptom Possible Cause Action Engine non-start Engine does not crank
Security system /Immobilizer
engaged
Engine in shut-down mode
ECM relay
Battery
Starting system
Engine seized
Check that the security system is disarmed
Read DTCs and refer to DTC Index in this
section for ECM relay tests
Ensure the battery is in fully charged and
serviceable condition
For starting system tests refer to the
relevant section of the workshop manual
For engine system tests refer to the relevant
section of the workshop manual Engine cranks, but does not fire
Engine breather system
disconnected/restricted
Ignition system
Fuel system
Electronic engine controls
Ensure the engine breather system is free
from restriction and is correctly installed
For ignition system tests refer to the
relevant section of the workshop manual
For fuel system tests refer to the relevant
section of the workshop manual
Read DTCs and refer to DTC Index in this
section for electronic engine control tests Engine cranks and fires, but will not
start
Evaporative emissions purge
valve
Fuel pump
Spark plugs
Ignition coil failure(s)
For purge valve tests refer to the relevant
section of the workshop manual
For fuel system tests refer to the relevant
section of the workshop manual
For ignition system tests refer to the
relevant section of the workshop manual Difficult to start Difficult cold start
Check engine coolant
level/anti-freeze content
Battery
Electronic engine controls
Exhaust gas recirculation
Check the engine coolant level and
condition. Refer to the relevant sections of
the workshop manual
Ensure the battery is in a fully charged and
serviceable condition. Refer to the battery

DTC Description Possible Causes Action B10AC-81
Cruise Control Switch -
invalid serial data received
The Engine Control Module
(ECM) has received an invalid
command from the steering
wheel switch pack Clear the DTC and press all the steering wheel
switches, re-check for DTCs. Refer to the
electrical circuit diagrams and check the Cruise
control switch circuit for open circuit, short to
power, short to ground, disconnected. Check
and install a new Steering Wheel Module (SWM) as required. B10AC-82 Cruise Control Switch - alive / sequence counter incorrect / not updated
Cruise Buttons alive counter is
not incrementing. Which
suggests that the LIN bus is
faulty
Steering Wheel Module (SWM) is
not connected
Steering Wheel Module (SWM)
failure Refer to the electrical circuit diagrams and
check the Cruise control switch circuit for open
circuit, short to power, short to ground,
disconnected. Check and install a new Steering
Wheel Module (SWM) as required. B10AC-83
Cruise Control Switch - value
of signal protection
calculation incorrect
Cruise buttons checksum
incorrect, incorrect cruise
switches fitted to vehicle Check and install new cruise switches as
required. B10AC-96
Cruise Control Switch -
component internal failure
Cruise control switch circuit,
open circuit, short to power,
short to ground, disconnected
Cruise Control Switch failure
Steering Wheel Module (SWM)
failure Check for related DTCs in other Central
Junction Box (CJB)s. Refer to the electrical
circuit diagrams and check the Cruise control
switch circuit for open circuit, short to power,
short to ground, disconnected. Check and
install a new cruise control switch as required.
Check and install a new Steering Wheel
Module (SWM) as required. B10FF-68
Ignition Control - Event
information
Spark plug(s) fault
Wiring harness fault
Ignition coil(s) fault Refer to repair manual and check spark plug(s)
for condition and security. Replace any
defective components as required. Refer to
electrical wiring diagrams and check ignition
coil circuit for intermittent open circuit, short
to power, short to ground. Check and install a
new coil(s) as required. B11DB-01
Battery Monitoring Module -
General Electrical Failure
Charging system fault Battery
monitoring signal line
circuit fault
Vehicle battery fault Refer to electrical wiring diagrams and check
charging system for faults. Perform any repairs
required. Refer to the electrical wiring
diagrams and check the Battery Monitoring
System (BMS) module circuit for open circuit,
short to ground, short to power. Refer to the
battery care manual and check and install a
new battery. B11DB-87
Battery Monitoring Module -
missing message
Battery signal line circuit fault Refer to the electrical wiring diagrams and
check the Battery Monitoring System (BMS)
module circuit for open circuit, short to ground,
short to power. B1206-68
Crash Occurred - event
information
Engine control Module (ECM) has
detected the vehicle has crashed
- event information DTC only Refer to the electrical circuit diagrams and
check the Engine Control Module (ECM) to
Restraints Control Module (RCM) circuit for
short to ground, short to power, open circuit.
Repair circuit as required, clear DTC and retest
system to confirm repair. C0031-00
Left Front Wheel Speed
Sensor - No sub type
information
Invalid data received from
Anti-lock Braking System (ABS)
module - left front wheel speed
signal fault Check Anti-lock Braking System (ABS) module
for related DTCs and refer to relevant DTC
Index. C0034-00
Right Front Wheel Speed
Sensor - No sub type
information
Invalid data received from
Anti-lock Braking System (ABS)
module - right front wheel speed
signal fault Check Anti-lock Braking System (ABS) module
for related DTCs and refer to relevant DTC
Index. C0037-00
Left Rear Wheel Speed
Sensor - No sub type
information
Invalid data received from
Anti-lock Braking System (ABS)
module - left rear wheel speed
signal fault Check Anti-lock Braking System (ABS) module
for related DTCs and refer to relevant DTC
Index. C003A-00
Right Rear Wheel Speed
Sensor - No sub type
information
Invalid data received from
Anti-lock Braking System (ABS)
module - right rear wheel speed
signal fault Check Anti-lock Braking System (ABS) module
for related DTCs and refer to relevant DTC
Index.

Visual Inspection

Mechanical Electrical
Low/contaminated fuel
Fuel supply/return line(s)
Fuel tank and filler pipe
Fuel leak(s)
Fuel filler cap
Fuel filter
Push connect fittings
Fuel pump
Fuses
Links
Relays
Fuel Pump Driver Module (FPDM)
Fuel pump module
Sensor(s)
Engine control module (ECM)
Rear Junction Box (RJB)
Restraints Control Module (RCM)
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 proceed to the DTC Index

Symptom Chart

Symptom Possible Causes Action Engine cranks, but does not
fire
Engine breather system
disconnected/restricted
Ignition system
Fuel system
Electronic engine control
Ensure the engine breather system is free from
restriction and is correctly installed
Check for ignition system, fuel system and electronic
engine control DTCs and refer to the relevant DTC
Index Engine cranks and fires, but
will not start
Evaporative emissions purge
valve
Fuel pump
Spark plugs
HT short to ground (tracking)
check rubber boots for
cracks/damage
Ignition system
Check for evaporative emissions, fuel system and
ignition system related DTCs and refer to the
relevant DTC Index Difficult cold start
Engine coolant level/anti-
freeze content
Battery
Electronic engine controls
Fuel pump
Purge valve
Check the engine coolant level and condition
Ensure the battery is in a fully charged and
serviceable condition
Check for electronic engine controls, engine
emissions, fuel system and evaporative emissions
system related DTCs and refer to the relevant DTC
Index Difficult hot start
Injector leak
Electronic engine control
Purge valve
Fuel pump
Ignition system
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
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
Check for fuel system related DTCs and refer to the
relevant DTC Index
Check for injector leak, install new injector as
required www.JagDocs.com

- Disadvantage: Scarring and hardening of the surface.
Flattening using a copper electrode.
- Small, sharp dents that face outwards can be worked on with a copper electrode.
Flattening using a flame and body files.

NOTE: When applied correctly, this method can be used with all the attached parts still in place (roof headlining,
wiring harnesses etc.).

- Small, soft dents (only slight stretching): Working at the edges of the dent in an inward spiral pattern, the dent
is heated with an oxyacetylene torch (torch size 1 - 2 mm, excess gas flame) to approx. 250° C.
- Working rapidly with a body file extracts heat from the edge area until the dent is flattened. Preferably alternate
between two files. This increases the amount of heat that can be extracted.

Safety measures

The electronic control modules (ECM) fitted to vehicles make it advisable to follow suitable precautions prior to carrying
out welding repair operations. Harsh conditions of heat and vibration may be generated during these operations which
could cause damage to the modules. In particular, it is essential to follow the appropriate precautions when
disconnecting or removing the airbag RCM.
Do not allow electronic modules or lines to come into contact with the ground connection or the welding electrode.
Seat belt anchorages are a safety critical. When making repairs in these areas, it is essential to follow design
specifications. Note that extra strength low alloy steel may be used for seat belt anchorages. Where possible, the
original production assembly should be used, complete with its seat belt anchorages, or the cut line should be so
arranged that the original seat belt anchorage is not disturbed.
All welds within 250mm (9.842) of seat belt anchorages must be carefully checked for weld quality, including spacing of
spot welds.
Remove the battery before carrying out welding work in its vicinity.
Utmost care must be taken when welding near the fuel tank or other components that contain fuel. If the tank filler
neck or a fuel line must be detached to allow access for welding work, then the fuel tank must be drained and removed.
Never weld, on components of a filled air conditioning system. The same applies if there is a risk of the air conditioning
system heating up.
Connect the ground connection of the electrical welder directly to the part that is to be welded. Make sure that there
are no electrically insulating parts between the ground connection and the welding point.
Adjacent vehicle parts and adjacent vehicles must be shielded against flying sparks and heat.

Pedestrian protection system

The pedestrian protection system is designed to mitigate injuries in a pedestrian collision with the vehicle. It does this by
utilizing a pair of pyrotechnic actuators to lift the hood away from the engine, creating a cushioned impact between the
pedestrian and the vehicle. It is essential that any repair or replacement operations do not affect the safe working of the
system.
For additional information, refer to: Pedestrian Protection System (501-20C Pedestrian Protection System, Description and Operation).

Resistance spot welding

Where resistance spot welds have been used in production, they must be reproduced with new spot welds in replacement
where possible. All such reproduction spot welds should be spaced 25 to 30mm apart.
Setting up the equipment and co-ordinating the welding parameters.

Equipment:
- Follow the equipment manufacturer's instructions for the equipment settings.
- Select the correct electrode arms (as short as possible).
- Align the electrode arms and tips exactly.
- Electrode tips should be convex (rough shaping with a file, fine shaping with a sanding block).
Body:
- Make sure that the flanges to be joined lie perfectly flat to one another.
- Prepare a bare metal joint surface (inside and outside).
Notes on technique/method:
- Carry out a test weld on a sample piece of the material coated in welding paste.
- If any metal parts are located between the electrode arms then there will be a loss of induction and therefore
power (adjust current setting).
- The power needs to be adjusted for high-strength low alloy steel.
- Repeated welding on old welding points often leads to poor quality welds.
- Keep the electrode tips as near as possible to an angle of 90° to the contact surface.
- Keep the pressure on the electrodes for a short period after finishing the weld.
- The electrodes work best if their shape is convex. Clean the contact surface of the electrodes regularly.
Resistance spot welding panels where the total thickness is 3 mm or more

For all repairs to modern Jaguar vehicles, spot-welding equipment should be suitable for reliable welding of zinc-plated,
high-strength and high-tensile steels in three or more layers, up to 5 mm total thickness. If these requirements are not
fulfilled, plug welding must be used for safety reasons. The electrical specifications (current, resistance, heat) of the
spot-welding equipment have different validity, depending upon the type of equipment. Therefore, it is essential that the
manufacturer's instructions are observed with regard to the actual welding performance.
www.JagDocs.com