ESP JAGUAR XFR 2010 1.G Manual PDF
[x] Cancel search | Manufacturer: JAGUAR, Model Year: 2010, Model line: XFR, Model: JAGUAR XFR 2010 1.GPages: 3039, PDF Size: 58.49 MB
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a decrease in engine torque. At the same time the ABS module will control the HCU to apply brake pressure to the relevant wheels to correct the understeer.
Electronic Brake Prefill (Vehicles With ACC Only)
Electronic brake prefill (Bosch ESP®plus8.1), senses any rapid throttle lift off, activating a small brake hydraulic pressure
build-up of approximately 3 to 5 bar (43.5 to 72.5 lbf/in²) in anticipation of the brakes being applied.
This application produces a quicker brake pedal response and consequently slightly shorter stopping distances. The system
supports vehicles with ACC (adaptive cruise control).
When the ABS module detects rapid throttle lift off (from the signals received from the ECM over the high speed CAN bus), it controls the HCU to apply a low brake pressure to assist in a quicker brake application.
Brake Vacuum Assist (3.0L Vehicles Only)
Operation of Brake Vacuum Assist generally occurs at the beginning of an ignition cycle when brake booster vacuum levels are
low; refer to Brake Booster Vacuum sensor, below.
Brake vacuum assist operation will be recognized by the driver experiencing a vibrating brake pedal and slight modulator noise.
This will be similar to that experienced when ABS system is operating.
As the engine warms up, Brake Vacuum Assist operation will become less frequent. However, it can be become more active
when vacuum levels are low due to driving at high-altitudes, or during frequent heavy-braking.
Noise levels during Brake Vacuum Assist may vary with initial system activity being the loudest observed. In some
circumstances initial activity may be interpreted as a 'thump' noise, particularly if there is no immediate and significant Brake
Vacuum Assist functionality.
In this circumstance system behavior is normal and should not be a cause for fault investigation.
Dynamic Stability Control Switch Component Description
Item Description 1 DSC switch The DSC switch is mounted in the floor console adjacent to the JaguarDrive selector.
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compartment, forward of the front suspension housing.
On petrol engine vehicles, a fluid cooler is located in front of the engine cooling radiator. Diesel models do not have a fluid
cooler.
Servotronic 2 adds electronic control and speed sensitive steering to the steering gear. The Servotronic 2 feature provides easy
and comfortable steering operation when parking, improved 'road feel' at increased road speeds and adds an integrated,
positive center feel feature which optimises steering wheel torque during high speed driving. The Servotronic 2 system is
controlled by software which is incorporated into the instrument cluster. The software responds to road speed signals and
controls the power assistance via a transducer valve located on the steering gear valve housing.
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18 Pinion 19 Steering gear rack bar 20 Valve sleeve The valve unit is an integral part of the steering gear. The principle function of the valve unit is to provide power assistance
(i.e. when parking) to optimize the effort required to turn the steering wheel.
The pinion housing of the valve is an integral part of the main steering gear casting. The pinion housing has four machined
ports which provide connections for pressure feed from the power steering pump, return fluid to the reservoir and pressure
feeds to each side of the cylinder piston.
The valve unit comprises an outer sleeve, an input shaft, a torsion bar and a pinion shaft. The valve unit is co-axial with the
pinion shaft which is connected to the steering column via the input shaft. The valve unit components are located in the
steering gear pinion housing which is sealed with a cap.
The outer sleeve is located in the main bore of the pinion housing. Three annular grooves are machined on its outer diameter.
PTFE (polytetrafluoroethylene) rings are located between the grooves and seal against the bore of the pinion housing. Holes
are drilled radially in each annular groove through the wall of the sleeve. The bore of the outer sleeve is machined to accept
the input shaft. Six equally spaced slots are machined in the bore of the sleeve. The ends of the slots are closed and do not
continue to the end of the outer sleeve. The radial holes in the outer sleeve are drilled into each slot.
The input shaft has two machined flats at its outer end which allow for the attachment of the steering column intermediate
shaft yoke. The flats ensure that the intermediate shaft is fitted in the correct position. The inner end of the input shaft forms
a dog-tooth which mates with a slot in the pinion shaft. The fit of the dog-tooth in the slot allows a small amount of relative
rotation between the input shaft and the pinion shaft before the dog-tooth contacts the wall of the slot. This ensures that, if
the power assistance fails, the steering can be operated manually without over stressing the torsion bar. The central portion of
the input shaft has equally spaced longitudinal slots machined in its circumference. The slots are arranged alternately around
the input shaft.
The torsion bar is fitted inside the input shaft and is an interference fit in the pinion shaft. The torsion bar is connected to the
input shaft by a drive pin. The torsion bar is machined to a smaller diameter in its central section. The smaller diameter allows
the torsion bar to twist in response to torque applied from the steering wheel in relation to the grip of the tyres on the road
surface.
The pinion shaft has machined teeth on its central diameter which mate with teeth on the steering gear rack. A slot, machined
in the upper end of the pinion shaft mates with the dog-tooth on the input shaft. The pinion shaft locates in the pinion
housing and rotates on ball and roller bearings.
Servotronic Valve
The Servotronic transducer valve is located in a port in the side of the steering gear valve housing. The valve is sealed in the
housing with an O-ring seal and is secured with two long screws into threaded holes in the housing. The Servotronic valve is a
transducer controlled valve which responds to control signals supplied from Servotronic software in the instrument cluster.
The Servotronic valve determines the hydraulic reaction at the steering gear rotary valve and controls the input torque required
to turn the steering wheel. The Servotronic system allows the steering to be turned with the optimum effort when the vehicle
is stationary or manoeuvred at slow speed. The hydraulic reaction changes proportional to the vehicle speed, with the required
steering effort increasing as the vehicle moves faster. At high speeds, the Servotronic system provides the driver with a good
feedback through the steering providing precise steering and improved stability.
The instrument cluster receives road speed signals from the ABS module and calculates the correct controlling signal for the Servotronic valve. The Servotronic software within the instrument cluster has a diagnostic capability which allows a Jaguar
approved diagnostic system to check the tune of the steering and retrieve fault codes relating to the Servotronic valve. Two
fault codes are stored relating to the valve for positive connection short to ground or battery and negative connection short to
ground or battery.
The Servotronic software within the instrument cluster also contains a number of steering maps which are selected via the car
configuration file depending on the vehicle model and tire fitment.
If a failure of the Servotronic valve or software occurs, the system will suspend Servotronic assistance and only a default level
of assistance will be available. Fault codes relating to the fault are stored in the instrument cluster. No warning lamps are
illuminated and the driver may be aware of the steering being 'heavier' than usual.
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1 Power steering fluid inlet port 2 Flow control valve 3 Power steering fluid outlet port 4 Variable Orifice 5 Pump rotor 6 High pressure 7 Adapter ring 8 Cam Ring 9 Low pressure The pump consists of a shaft containing a number of slots into which vanes are inserted and these vanes run within a cam ring
in the pump body. The centerline of the shaft is not concentric with that of the bore of the body and this creates the expanding
and contracting cavities that form the pumping action.
The vanes rotate within the cam ring and are driven by the shaft. As the vanes rotate, the cam ring causes the space between
the vanes to increase. This causes a depression between the vanes and fluid is drawn from the reservoir via the suction hose
into the space between the vanes. As the shaft rotates, the inlet port is closed to the vanes which have drawn in fluid,
trapping the fluid between the vanes. The cam ring causes the space between the vanes to reduce and consequentially
compresses and pressurizes the hydraulic fluid trapped between them. Further rotation of the shaft moves the vanes to the
outlet port. As the vanes pass the port plate the pressurized fluid passes from the pump outlet port into the pressure hose to
the steering gear.
The cam ring in the pump body can move within the valve body. By moving the cam ring it is possible to vary the eccentricity of
the shaft and the vanes in relation to the cam ring. As the eccentricity is decreased, the volume of hydraulic fluid trapped
between the vanes decreases, maintaining the flow in response to pump speed. This reduces the load required to turn the
pump and therefore improves engine output and economy. This allows the flow rate to be matched to the system demands and
increased flow rate is only required when the steering wheel is turned.
The pump has an internal regulating valve which controls the eccentricity of the cam ring and therefore varies the flow rate
according to demand. The regulating relief valve limits the maximum pressure supplied to the steering gear to 110 bar (1595
lbf in2) ± 4 bar (58 lbf in2) and also limits the maximum flow to 8.5 l/min (1.86 gal/min) ± 0.5 l/min (0.1 gal/min) regardless
of engine speed.
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16 Ball (12 off) 17 Distance keeper 18 Crash tube The column comprises a cast magnesium mounting bracket which provides the attachment to the cross-beam. Attached to the
mounting bracket is a rake lever which is attached to the mounting bracket at the lower end with two pivot bearings. The
bearings allow the rake lever to rotate upwards or downward to adjust the column rake.
The rake lever also provides for the attachment of the rake housing which can slide within the lever to provide the reach
adjustment. Within the rake housing is the axial housing which is supported on each side with 6 ball bearings which allow the
rake housing to move forward or backwards. The bearings on each side are arranged in groups of 3 bearings and are separated
by a distance keeper which allows the housing to supported on bearings along its length. Within the axial housing is a tube
which is supported at the upper end of the column on the upper bearing. The tube has a central splined hole which provides for
the fitment of the splined shaft. The splined shaft can slide within the tube on the splines when the column reach is adjusted
or the column collapses in a crash condition. The splined shaft also passes rotary motion from the steering wheel through the
length of the column to the outer clamping yoke which is supported on the lower bearing.
The electric steering column lock is attached to the top of the rake lever. A lock bolt within the steering column lock engages in
one of 8 slots in the locking sleeve located at the lower end of the column preventing rotation of the steering wheel. The
locking sleeve is retained by a tolerance ring which in turn is located on the outer diameter of the tube yoke. The tolerance
ring allows a specified amount of torque to be applied to the splined shaft before it slips, preventing damage to the column
lock due to excessive force being applied to the steering wheel when the lock is engaged. The tolerance ring is designed to
slip on the splined shaft when the applied torque exceeds the fitted slip load of 200 Nm minimum. Repeated rotation of the
lock collar will reduce its slipping torque to 100 Nm minimum. The lock is controlled by the CJB.
A steering angle sensor is located at the upper end of the steering column and is attached to the crash adaptor. The sensor
measures steering rotation via a toothed wheel located on the splined tube at the upper end of the column. The sensor
receives a power supply from the CJB and supplies 2 signals (A and B) relating to the steering rotation to the ABS (anti-lock brake system) module. The module transmits this data on the high speed CAN bus for use by other vehicle systems. Refer to: Anti-Lock Control - Stability Assist (206-09 Anti-Lock Control - Stability Assist, Description and Operation).
The steering column is adjustable electrically, for reach and rake. The adjustment mechanism comprises an electric adjustment
motor, a lead screw, a rake solenoid, a reach solenoid, a reach clutch and a rake clutch. The column adjustment is controlled
manually using a joystick switch located on the LH (left-hand) side of the column lower cowl. The joystick can be moved
forward and backward to adjust the column reach in and out and moved up and down to adjust the rake. The switch selection
energizes the adjustment motor in the applicable direction and also engages the applicable solenoid and clutch.
When the joystick switch is rotated to the 'auto' position, the steering column will adjust to the uppermost rake position when
the ignition is switched off. It will re-adjust to the position corresponding to the memory position for the remote handset when
the ignition is switched on.
The memory function of the electric column is linked to and controlled by the driver's seat module. The module provides for the
storage of three separate memory positions which are stored against 3 individual remote handsets.
Refer to: Seats (501-10 Seating, Description and Operation).
The steering wheel locates on a splined shaft in the upper column assembly and is secured with a bolt. The steering wheel
houses the driver's airbag and switches for the audio system, gear change and speed control. A clockspring is used to connect
the steering wheel electrical components to the vehicle harness.
Two plastic shrouds are fitted to the upper column assembly. The lower shroud is fitted with an energy absorbing foam pad to
minimize leg injury in the event of an accident.
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8 Steering column LH (left-hand) multifunction switch 9 Steering column RH (right-hand) multifunction switch 10 Instrument cluster 11 Speed control switches 12 Audio/telephone switches 13 Clockspring 14 Information and entertainment module 15 Media Oriented System Transport (MOST) ring connection to other vehicle systems 16 Medium speed CAN (controller area network) bus to other vehicle systems
LEFT HAND MULTIFUNCTION SWITCH
Turn Signal Indicators System Operation
The instrument cluster outputs a reference voltage to the turn signal indicator switch. When the switch is in the central off
position, the voltage flows through 3 resistors which are connected in series and back to the instrument cluster which monitors
the signal and determines the turn signal indicators are off. This information is broadcast on the medium speed CAN bus to the CJB.
When the switch is operated in the LH turn signal indicator position, the reference voltage from the instrument cluster is routed via 1 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB. The CJB activates the applicable turn signal indicators until it receives an off message from the instrument cluster.
When the switch is operated in the RH turn signal indicator position, the reference voltage from the instrument cluster is routed via 2 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB. The CJB activates the applicable turn signal indicators until it receives an off message from the instrument cluster.
Lighting Control Switch
The instrument cluster outputs 2 reference voltages to the rotary lighting control switch; one feed being supplied to the light
selection function of the switch and the second feed being supplied to the autolamp exit delay function. The switch position is
determined by instrument cluster by the change in returned signal voltage which is routed through up to 4 resistors in series
depending on the selection made.
When the lighting control switch is in the off position, the reference voltage flows through 1 of the resistors. The returned
signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that no lighting selection is made. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.
When the lighting control switch is in the sidelamp position, the reference voltage flows through 2 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the sidelamps. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.
When the lighting control switch is in the headlamp position, the reference voltage flows through 3 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the headlamps. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp or exit delay has not been selected.
When the lighting control switch is in the autolamp position, the reference voltage flows through 4 of the resistors. The
returned signal voltage is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the autolamp function. The reference voltage to the autolamp exit delay switch is routed through 4 resistors which is detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB that autolamp has been selected.
Autolamp Exit Delay
When the lighting control switch is in any of the autolamp exit delay position, the lighting control switch reference voltage
flows through 4 of the resistors. The returned signal voltage is detected by the instrument cluster which outputs a message on
the medium speed CAN bus to the CJB that autolamps has been selected.
Depending on the selected position, the reference voltage to the autolamp exit delay switch is routed through 3, 2 or 1
resistors which is detected by the instrument cluster. The cluster outputs a message on the medium speed CAN bus to the CJB that autolamp exit delay period has been selected at 30, 60 or 120 seconds respectively.
Trip Function Button
The instrument cluster outputs a reference voltage to the trip function button. When the function button is pressed a ground
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path is completed and a signal voltage is returned to the instrument cluster via a resistor. The returned reference voltage is
detected by the instrument cluster and performs the requested trip function.
RIGHT HAND MULTIFUNCTION SWITCH
The instrument cluster outputs 4 separate reference voltages to the following switch functions:
Wash/wipe switch
Intermittent wipe switch
Master wiper switch
Flick wipe switch.
Wash/Wipe Switch
The reference voltage is supplied to one of two resistors connected in parallel. When the switch is not being operated the
current flows through one resistor and the returned signal voltage is monitored by the instrument cluster. When the wash/wipe
switch is operated, a connection is made and the current flows through the second resistor. The change in signal voltage is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the wash/wipe function.
Intermittent Delay/Auto Wipe Switch
The reference voltage is supplied to the switch and can pass through up to 7 resistors, connected in series, for intermittent
delay selections and the auto wipe function.
When the rotary switch is in the auto position the reference voltage flows through 1 resistor. The returned signal voltage is
detected by the instrument cluster which determines auto wipe is selected. The instrument cluster outputs a message on the
medium speed CAN bus to the CJB to activate the auto wipe function.
With the rotary switch in one of the intermittent positions, the reference voltage is routed through up to 7 of the resistors
depending on the delay period selected. The returned signal voltage is detected by the instrument cluster which determines
selected delay period. The instrument cluster outputs a message on the medium speed CAN bus to the CJB to activate the selected intermittent wipe function.
NOTE: The delay period for the intermittent selections can vary according to vehicle speed.
Master Wiper Switch
The reference voltage supplied from the instrument cluster to the master wiper switch. The voltage can pass through up to 4
resistors connected in series.
When the switch is in the off position, the reference voltage passes through 4 resistors and the returned voltage is monitored
by the instrument cluster. The instrument cluster outputs a message on the medium speed CAN bus to the CJB that no wiper selections have been requested.
With the switch in the intermittent, slow wipe or fast wipe position, the reference voltage passes through 3, 2 or 1 resistors
respectively. The returned signal voltage is detected by the instrument cluster which determines selected delay period. The
instrument cluster outputs a message on the medium speed CAN bus to the CJB to activate the selected wipe function. Flick Wipe Switch
The reference voltage is supplied to one of two resistors connected in parallel. When the switch is not being operated the
current flows through one resistor and the returned signal voltage is monitored by the instrument cluster. When the flick wipe
switch is operated, a connection is made and the current flows through the second resistor. The change in signal voltage is
detected by the instrument cluster which outputs a message on the medium speed CAN bus to the CJB to activate the flick wipe function.
STEERING COLUMN ADJUSTMENT SWITCH
The instrument cluster supplies 2 reference voltages to the column adjustment switch.
The first reference voltage is supplied to the joystick switch. When the switch is moved to one of its 4 positions, the switch
contact is completed and the reference voltage is passed through one of 4 different resistors with different values. The
returned signal voltage is measured by the instrument cluster which determines the selected column adjust request. The
instrument cluster outputs a supply to the steering column adjustment motor and energizes the applicable clutch solenoid to
move the column to the desired position.
The second reference voltage is supplied to the auto/manual selection of the switch. When the switch is in the auto position,
the reference voltage passes directly through the switch contacts and is measured by the instrument cluster. The instrument
cluster outputs a message on the medium speed CAN bus to the driver seat module which responds with the recorded memory position setting. The instrument cluster then activates the column adjustment motor and clutch solenoids to move the column
to the memorized position. When the switch is in the manual position the reference circuit is broken. The instrument cluster
detects the broken circuit and allows manual operation of the column adjustment switch to move the column.
HEATED STEERING WHEEL
The heated steering wheel receives a battery power supply via the CJB. The heated steering wheel is controlled by the driver using a selection on the TSD. When the driver selects the heated steering wheel to be active, the request is passed from the
TSD on the MOST ring to the information and entertainment module. The information and entertainment module converts the
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engine oil).
Oil Consumption Test
The amount of oil an engine uses will vary with the way the vehicle is driven in addition to normal engine-to-engine variation.
This is especially true during the first 16,100 km (10,000 miles) when a new engine is being broken in or until certain internal
components become conditioned. Vehicles used in heavy-duty operation may use more oil. The following are examples of
heavy-duty operation:
Trailer towing applications
Severe loading applications
Sustained high speed operation
Engines need oil to lubricate the following internal components:
Cylinder block cylinder walls
Pistons and piston rings
Intake and exhaust valve stems
Intake and exhaust valve guides
All internal engine components
When the pistons move downward, a thin film of oil is left on the cylinder walls. As the vehicle is operated, some oil is also
drawn into the combustion chambers past the intake and exhaust valve stem seals and burned.
The following are examples of conditions that can affect oil consumption rates:
Engine size
Operator driving habits
Ambient temperatures
Quality and viscosity of oil
Engine is being run in an overfilled condition (check the oil level at least five minutes after a hot shutdown with the
vehicle parked on a level surface. The oil level should not be above the top of the cross-hatched area and the letter "F"
in FULL).
Operation under varying conditions can frequently be misleading. A vehicle that has been run for several thousand miles on
short trips or in below-freezing ambient temperatures may have consumed a "normal" amount of oil. However, when checking
the engine oil level, it may measure up to the full mark on the oil level indicator due to dilution (condensation and fuel) in the
engine crankcase. The vehicle then might be driven at high speeds on the highway where the condensation and fuel boil off.
The next time the engine oil is checked it may appear that a liter of oil was used in about 160 km (100 miles). Oil
consumption rate is about one liter per 2,400 km (1,500 miles).
Make sure the selected engine oil meets Jaguar specification and the recommended API performance category "SG" and SAE
viscosity grade as shown in the vehicle Owner's Guide. It is also important that the engine oil is changed at the intervals
specified for the typical operating conditions.
The following diagnostic procedure is used to determine the source of excessive oil consumption.
NOTE: Oil use is normally greater during the first 16,100 km (10,000 miles) of service. As mileage increases, oil use
decreases. High speed driving, towing, high ambient temperature and other factors may result in greater oil use.
1. Define excessive consumption, such as the number of miles driven per liter of oil used. Also determine customers
driving habits, such as sustained high speed operation, towing, extended idle and other considerations.
2. Verify that the engine has no external oil leaks as described under Engine Oil Leaks in this section.
3. Carry out an oil consumption test:
Run the engine to normal operating temperature. Switch engine OFF and allow oil to drain back for at least five
minutes .
With vehicle parked on level surface, check the engine oil level.
If required, add engine oil to set level exactly to the FULL mark.
Record the vehicle mileage.
Instruct the customer to return for a level check after driving the vehicle as usual for 1,610 km (1000 miles).
Check the oil level under the same conditions and at the same location as the initial check.
NOTE: If the oil consumption rate is unacceptable go to Step 4.
4. Check the Positive Crankcase Ventilation (PCV) system. Make sure the system is not plugged.
5. Check for plugged oil drain-back holes in the cylinder head and cylinder block.
6. If the condition still exists after carrying out the above tests go to step 9.
7. Carry out a cylinder compression test. Refer to the Compression Test procedure in this section. This can help determine
the source of oil consumption such as valves, piston rings or other areas.
8. Check valve guides for excessive guide clearance. Install new valve stem seals after verifying valve guide clearance.
9. Worn or damaged internal engine components can cause excessive oil consumption. Small deposits of oil on the tips of
the spark plugs can be a clue to internal oil consumption.
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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
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7 Bleed pipe connection (containing check valve) The body of the coolant pump contains an impeller attached to a shaft supported in a bearing assembly. The impeller is driven
by a pulley, pressed on to the front of the shaft, which is driven by the accessory drive belt. For additional information, refer to
303-05E Accessory Drive - 5.0L, Vehicles Without: Supercharger or 303-05F - 5.0L, Vehicles With: Supercharger.
Two coolant outlet flanges attach the coolant pump to the front of the cylinder heads. A pipe connects a further coolant outlet
to a pipe from the engine oil cooler. A bleed connector is installed in the front of the coolant pump, adjacent to the coolant
inlet connection from the thermostat. A check valve is incorporated into the bleed connection.
THERMOSTAT
Item Description 1 Screw (3 off) 2 Lower body 3 Upper body 4 Thermostat 5 Seal The thermostat is a multi-stage device located in the coolant pump inlet to provide fast response and control of the engine
outlet temperature.
The thermostat allows rapid engine warm-up by preventing coolant flow through the radiator and by limiting coolant flow
through the cylinder block when the engine is cold. During warm-up and at engines speeds above approximately 1800 rev/min,
a by-pass valve opens to control the coolant flow and pressure, to protect the engine components. When the thermostat
opening reaches 6 mm (0.24 in.), the by-pass flow is shut-off. When the thermostat opening exceeds 6 mm (0.24 in.), the
radiator coolant flow is further controlled up to the point where the thermostat is fully open. At this point maximum radiator
coolant flow is achieved to provide maximum cooling.
On both naturally aspirated and supercharger vehicles, the thermostat begins to open at 88 - 90 °C (190 - 194 °F) and is fully
open at 102 °C (216 °F).