
Press and hold the DSC switch for less than 10 seconds.
The message center will temporarily display either Trac DSC or DSC ON.
The warning indicator in the instrument panel will illuminate while Trac DSC is selected.
The warning indicator will flash when DSC or Trac DSC is active.
NOTE: If cruise control is engaged, it will automatically disengage if DSC activates.
Refer to: Speed Control (310-03 Speed Control - 2.7L V6 - TdV6, Description and Operation).
Corner Brake Control
CBC (corner brake control) influences the brake pressures, below and within DSC and ABS thresholds, to counteract the yawing moment produced when braking in a corner. CBC produces a correction torque by limiting the brake pressure on one side of the
vehicle.
Electronic Brake Force Distribution
EBD (electronic brake force distribution) limits the brake pressure applied to the rear wheels. When the brakes are applied, the
weight of the vehicle transfers forwards, reducing the ability of the rear wheels to transfer braking effort to the road surface.
This may cause the rear wheels to slip and make the vehicle unstable.
EBD uses the ABS braking hardware to automatically optimize the pressure to the rear brakes, below the point where ABS is normally invoked.
NOTE: Only the rear brakes are controlled by the EBD function.
Electronic Traction Control
ETC (electronic traction control) attempts to optimize forward traction by reducing engine torque, or by applying the brake of a
spinning wheel until traction is regained.
ETC is activated if an individual wheel speed is above that of the vehicle reference speed (positive slip) and the brake pedal is
not pressed. The brake is applied to the spinning wheel, allowing the excess torque to be transmitted to the non-spinning
wheel through the drive line. If necessary, the ABS module also sends a high speed CAN bus message to the ECM to request a reduction in engine torque.
When the DSC function is selected off using the DSC switch, the braking and engine torque reduction features are both
disabled, except when the JaguarDrive control is in winter mode. When the JaguarDrive control is in winter mode, selecting the
DSC function off retains the braking and engine torque reduction features, but reduces intervention levels compared to DSC
and Trac DSC modes.
Emergency Brake Assist
EBA (emergency brake assist) assists the driver in emergency braking situations by automatically increasing the applied
braking effort. The ABS module invokes EBA when: The brake pedal is rapidly pressed.
The brake pedal is pressed hard enough to bring the front brakes into ABS operation.
When the brake pedal is rapidly pressed, the ABS module increases the hydraulic pressure to all of the brakes until the threshold for ABS operation is reached. This action applies the maximum braking effort for the available traction. The ABS module monitors for the sudden application of the brakes, using inputs from the brake pedal switch and from the pressure
sensor within the HCU (hydraulic control unit). With the brake pedal pressed, if the rate of increase of hydraulic pressure
exceeds the predetermined limit, the ABS module invokes emergency braking.
When the brake pedal is pressed hard enough to bring the front brakes into ABS operation, the ABS module increases the hydraulic pressure to the rear brakes up to the ABS threshold.
EBA operation continues until the driver releases the brake pedal, sufficiently for the hydraulic pressure in the HCU to drop below a threshold value stored in the ABS module.
Engine Drag-Torque Control
EDC (engine drag-torque control) prevents wheel slip caused by any of the following: A
sudden decrease in engine torque when the accelerator is suddenly released.
A downshift using the Jaguar sequential shift function on automatic transmission vehicles.
When the ABS module detects the onset of wheel slip without the brakes being applied, the ABS module signals the ECM via the high speed CAN bus to request a momentary increase in engine torque.
Understeer Control
Understeer Logic Control is a proactive system which monitors the vehicle for understeer by comparing signals from the yaw
rate and lateral acceleration sensor with signals from the steering angle sensor and wheel speed sensors. www.JagDocs.com

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.

With the control valve (7) OPEN and the engine idling, the following system pressures may be checked:
During turning when static (dry parking pressure).
When the steering is held on full lock (maximum system pressure or pressure relief).
With the steering at rest (idle pressure or back pressure).
CAUTIONS:
To avoid excessive heating of the power steering pump when checking the pressure, do not close the valve for more than
5 seconds maximum.
When checking the pump pressure DO NOT drive the vehicle with the test equipment installed.
With the control valve (7) CLOSED the power steering pump maximum output pressure can be checked.
Removing Test Equipment
To remove the test equipment:
Install a hose clamp on the reservoir to power steering pump hose.
Removing the test equipment is a reversal of the installation instructions.
Install a new 'O' ring seal (9) to the power steering pump high pressure outlet to hose connection.
Install the original hose to the power steering pump.
Remove the clamp from the reservoir to the power steering pump hose.
Top-up the reservoir fluid.
Bleed the power steering system.
REFER to: Power Steering System Bleeding (211-00 Steering System - General Information, General Procedures).
Description of Terms General Steering System Noises
Boom
Rhythmic sound like a drum roll or distant thunder. May cause pressure on the ear drum.
Buzz
Low-pitched sound, like a bee. Usually associated with vibrations.
Chatter
Rapidly repeating metallic sound.
Chuckle
Rapid noise that sounds like a stick against the spokes of a spinning bicycle wheel.
Chirp
High pitched rapidly repeating sound, like chirping birds.
Click
Light sound, like a ball point pen being clicked.
Click/Thump
Heavy metal-to-metal sound, like a hammer striking steel.
Grind
Abrasive sound, like a grinding wheel or sandpaper rubbing against wood.
Groan/Moan
Continuous, low-pitched humming sound.
Groan/Howl
Low, guttural sound, like an angry dog.
Hiss
Continuous sound like air escaping from a tire valve.

1 Yoke 2 Upper collapse shaft 3 Flexible coupling 4 Shaft plate 5 Rivet (4 off) 6 Upper tube 7 Plastic sleeve 8 Boot 9 Bearing (4 off) 10 Teeth tube 11 Lower shaft 12 Yoke clamp bolt (2 off) 13 Bearing (4 off) 14 Lower yoke 15 Spider 16 Upper yoke The lower shaft assembly comprises 2 splined shafts connected by a universal joint in the center.
The upper collapse shaft has a flexible couple at its upper end. The flexible coupling controls axial and torsional movements
and also assists with noise and vibration damping. The flexible coupling is fitted with a shaft plate which has a boss with
machined flats on it. The flats provide positive location on the upper column outer clamping yoke. A cut-out in the boss allows
for the fitment of a clamping bolt to secure the upper column outer clamping yoke. The cut-out ensures that the lower shaft
assembly can only be fitted in one orientation.
The upper collapse shaft is connected to the stopper plate of the flexible coupling with splines. The stopper plate is connected
to the shaft plate via the flexible coupling and is secured with rivets. The upper collapse shaft has a series of splines which
engage with the upper tube. The splines allow the upper collapse shaft to slide into the upper tube in the event of an
accident.
The upper tube is positively connected to the upper half of the yoke of the universal joint. A plastic tube is located around the
upper tube and provides for the attachment of a boot which seals the lower shaft assembly where it passes through the
vehicle bulkhead. LOWER SHAFT ASSEMBLY

cooling jets and the timing chain lubrication jets.
The oil returns to the oil pan under gravity. Large drain holes through the cylinder heads and cylinder block ensure the rapid
return of the oil to the sump pan. System replenishment is through the oil filler cap on the LH cylinder head cover.
An oil evacuation tube is installed to allow oil to be drawn from the sump pan. The upper end of the oil evacuation tube is
located under the oil filler cap.
An oil drain plug is installed in the RH side of the sump pan.
Oil Pump Nominal Operating Pressures
Engine Speed, rev/min Temperature, °C (°F) Pressure, bar (lbf/in2
) Idle 20 (68) 2.0 (29.0) 1500 20 (68) 6.0 (87.0) 3000 40 (104) 6.2 (90.0) 3000 110 (230) 5.0 (72.5) 3000 130 (266) 4.0 (58.0) Oil Level Monitoring
Oil level monitoring is provided by an oil level and temperature sensor that measures the oil level in the sump pan. The oil
level can be displayed in the message center of the instrument cluster.
The oil level and temperature sensor supplies the ECM with a signal containing the level and temperature of the oil in the sump pan. The oil level and temperature sensor is secured to the bottom of the sump pan with three screws and sealed with a
gasket.
The oil level and temperature sensor sends an ultrasonic pulse vertically upward and measures the time taken for the pulse to
be reflected back from the top surface of the oil. This time is compared with the time taken for an ultrasonic pulse to travel a
reference distance within the oil level and temperature sensor to determine the oil level. The oil level reading is combined with
the oil temperature reading and transmitted in a PWM signal to the ECM.
Oil Level and Temperature Sensor Specifications
Feature Details Power source Battery Voltage Level Accuracy ±2 mm (±0.08 in.) at temperatures of -30 °C (-22 °F)) and above; (±4 mm (±0.16 in.) at
temperatures below -30 °C (-22 °F)) Temperature Accuracy ±2 °C (±3.6 °F) Operating Level Range 116 to 147 mm (4.57 to 5.79 in.)

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).

Published: 11-May-2011
Evaporative Emissions - V8 5.0L Petrol/V8 S/C 5.0L Petrol - Evaporative Emissions - System Operation and Component Description
Description and Operation
System Operation DIAGNOSTIC MODULE - TANK LEAKAGE PUMP (NAS ONLY)
To check the fuel tank and the EVAP (evaporative emission) system for leaks, the ECM (engine control module) operates the
DMTL pump and monitors the current draw. Initially, the ECM establishes a reference current by pumping air through the reference orifice and back to atmosphere. Once the reference current is determined, the ECM closes the change-over valve, which seals the EVAP system. The EVAP canister purge valve remains de-energized and is therefore closed. The output from the air pump is diverted from the reference orifice and into the EVAP system.
When the change-over valve is closed, the load on the air pump falls to zero. Providing there are no leaks, the air pump will
begin to pressurize the EVAP system and the load and current draw in the pump increases. By monitoring the rate and level of the current increase, the ECM can determine if there is a leak in the EVAP system.
During normal vehicle operation, 15 seconds after the engine has started, the ECM energizes the heating element in the pump to prevent condensation formation and possible incorrect readings. The heater remains energized until either the engine and
ignition are off (if no DMTL test is running) or until after the DMTL test is completed.
Leaks are classified as:
Minor - equivalent to a hole diameter of 0.5 to 1.0 mm (0.02 to 0.04 in.).
Major - equivalent to a hole diameter of 1.0 mm (0.04 in.) or greater.
The ECM performs a check for major leaks each time the ignition is switched off, providing the following conditions are met: The vehicle speed is zero.
The engine speed is zero.
The atmospheric pressure is above 70 kPa (10.15 lbf/in2
), i.e. the altitude is less than approximately 3047 m (10000
feet).
The ambient temperature is between 0 and 40 °C (32 and 104 °F).
The EVAP canister vapor concentration factor is 5 or less (where 0 is no fuel vapor, 1 is stoichiometric fuel vapor and greater than 1 is rich fuel vapor).
The fuel tank level is valid and between 15 and 85% of nominal capacity.
The engine running time during the previous cycle was more than 10 minutes.
The battery voltage is between 10 and 15 volts.
The last engine off time was more than 180 minutes.
No errors are detected with the EVAP components, the ambient air temperature and the fuel level.
NOTE: A leak test can be performed using a Jaguar recognized diagnostic tool. This overrides the above conditions and is
useful for checking correct system and component operation.
The ECM performs a check for minor leaks after every 2nd major leak check.
When the leak check is complete, the ECM stops the DMTL pump and opens (de-energizes) the change-over valve.
If the fuel filler cap is opened or refueling is detected during the leak check, by a sudden drop in the current draw or a rise in
the fuel level, the ECM aborts the leak check.
If a leak is detected during the check, the ECM stores an appropriate fault code in its memory. If a leak is detected on two consecutive checks, the ECM illuminates the MIL (malfunction indicator lamp) in the instrument cluster on the next drive cycle. The duration of a leak check can be between 60 and 900 seconds depending on the results and fuel tank level.
EVAP CANISTER PURGE VALVE
The ECM waits until the engine is running above 55 °C (131 °F) coolant temperature with closed loop fuel operational before the purging process is activated. Under these conditions the engine should be running smoothly with no warm up enrichment.
The EVAP canister purge valve duty (and flow) is initially ramped slowly because the vapor concentration is unknown (a sudden increase in purge could cause unstable engine running or cause it to stall due to an extremely "rich" air/fuel mixture). The
concentration is then determined from the amount of adjustment that the closed loop fueling is required to make to achieve
the target AFR (air fuel ratio). Once the concentration has been determined, the purge flow can be increased rapidly and the
injected fuel can be pro-actively adjusted to compensate for the known purge vapor and the target AIR control is maintained.
When the purging process is active, fresh air is drawn into the EVAP canister via the DMTL filter and pump on NAS vehicles, or via the vent port on the EVAP canister of non NAS vehicles.

DRIVE CLUTCHES
Item Description 1 Input shaft 2 Main pressure supply port 3 Piston 4 Cylinder – external plate carrier 5 Clutch plate assembly 6 Baffle plate 7 Diaphragm spring 8 Output shaft 9 Bearing 10 Dynamic pressure equalization chamber 11 Piston chamber 12 Lubrication channel There are three drive clutches and two brake clutches used in the ZF 6HP28 transmission. Each clutch comprises one or more
friction plates dependent on the output controlled. A typical clutch consists of a number of steel outer plates and inner plates
with friction material bonded to each face.
On 5.0L SC (supercharger) and 3.0L diesel models, the uprated transmission includes additional clutch plates to enable the
transmission to manage the additional power output from these engines.
The clutch plates are held apart mechanically by a diaphragm spring and hydraulically by dynamic pressure. The pressure is
derived from a lubrication channel which supplies fluid to the bearings etc. The fluid is passed via a drilling in the output shaft
into the chamber between the baffle plate and the piston. To prevent inadvertent clutch application due to pressure build up
produced by centrifugal force, the fluid in the dynamic pressure equalization chamber overcomes any pressure in the piston
chamber and holds the piston off the clutch plate assembly.
When clutch application is required, main pressure from the fluid pump is applied to the piston chamber from the supply port.
This main pressure overcomes the low pressure fluid present in the dynamic pressure equalization chamber. The piston moves,
against the pressure applied by the diaphragm spring, and compresses the clutch plate assembly. When the main pressure
falls, the diaphragm spring pushes the piston away from the clutch plate assembly, disengaging the clutch.
PLANETARY GEAR TRAINS
The planetary gear trains used on the ZF 6HP28 transmission comprise a single web planetary gear train and a double web
planetary gear train. These gear trains are known as Lepelletier type gear trains and together produce the six forward gears
and the one reverse gear.
Single Web Planetary Gear Train
The single web planetary gear train comprises:
Sunwheel
Three (naturally aspirated versions) or four (5.0L SC and 3.0L diesel versions) planetary gears Planetary gear carrier (spider)
Ring gear or annulus. Multiplate Drive or Brake Clutch – Typical www.JagDocs.com