wheel torque JAGUAR XFR 2010 1.G Service Manual

Power Flow 2nd Gear



The JaguarDrive selector and the selector spool valve are in the 'D' position. Engine torque is transmitted from the torque
converter turbine shaft to the ring gear 1 of the single web planetary gear train and the outer plate carrier of clutch 'E'.

Ring gear 1 drives the planetary gears which rotate around sunwheel 1. This drives the planetary gear carrier 1 and also the
outer plate carrier of clutch 'A' and the inner plate carrier of clutch 'B'.

When clutch 'A' is engaged, sunwheel 3 in the double web planetary gear train is driven and meshes with the short planetary
gears.

Sunwheel 2 is locked to the transmission housing by brake clutch 'C'. The long planetary gears, which are also meshed with the
short planetary gears, roll around the fixed sunwheel 2 and transmit drive to the double web planetary gear train carrier and
ring gear 2 in the direction of engine rotation.


NOTE: Refer to 'Shift Elements' illustration for key

NOTE: Refer to 'Shift Elements' illustration for key



Power Flow 4th Gear



The JaguarDrive selector and the selector spool valve are in the 'D' position. Engine torque is transmitted from the torque
converter turbine shaft to ring gear 1 of the single web planetary gear train and the outer plate carrier of clutch 'E'.

Ring gear 1 drives the planetary gears which rotate around sunwheel 1. This drives the planetary gear carrier 1 and also the
outer plate carrier of clutch 'A' and the inner plate carrier of clutch 'B'.

When clutch 'A' is engaged, sunwheel 3 in the double web planetary gear train is driven and meshes with the short planetary
gears.
The double web planetary gear carrier is driven via clutch 'E' which is engaged. The long planetary gears, which are also www.JagDocs.com

meshed with the short planetary gears and the double web planetary gear carrier, drive ring gear 2 in the direction of engine
rotation.


NOTE: Refer to 'Shift Elements' illustration for key



Power Flow 5th Gear



The JaguarDrive selector and the selector spool valve are in the 'D' position. Engine torque is transmitted from the torque
converter turbine shaft to ring gear 1 of the single web planetary gear train and the outer plate carrier of clutch 'E'.

Ring gear 1 drives the planetary gears which rotate around sunwheel 1. This drives the planetary gear carrier 1 and also the
outer plate carrier of clutch 'A' and the inner plate carrier of clutch 'B'.
When clutch 'A' is engaged, sunwheel 3 in the double web planetary gear train is driven and meshes with the short planetary

Clutch brake 'C' is applied which locks sunwheel 2 to the transmission housing.

Clutch 'E' is engaged and drives the double web planetary gear carrier. This causes the long planetary gears to rotate around
the fixed sunwheel 2 and transmit drive to ring gear 2 which is driven in the direction of engine rotation.


NOTE: Refer to 'Shift Elements' illustration for key



Power Flow Reverse Gear



The JaguarDrive selector and the selector spool valve are in the 'R' position. Engine torque is transmitted from the torque
converter turbine shaft to ring gear 1 of the single web planetary gear train and the outer plate carrier of clutch 'E'.

Ring gear 1 drives the planetary gears of the single web planetary gear train which rotate around the fixed sunwheel 1. This
transmits the drive to the single web planetary gear carrier, the outer plate carrier of clutch 'A' and the inner plate carrier of

1 Transmission selected gear status 2 MIL (malfunction indicator lamp) 3 Message center The instrument cluster is connected to the TCM via the high speed CAN bus. Transmission status is transmitted by the TCM and displayed to the driver in one of two displays in the instrument cluster. For additional information, refer to 413-01
Instrument Cluster.

Malfunction Indicator Lamp

The MIL (malfunction indicator lamp) is located in the tachometer in the instrument cluster. Transmission related faults which
may affect the vehicle emissions output will illuminate the MIL.
The MIL is illuminated by the ECM (engine control module) on receipt of a relevant fault message from the TCM on the high speed CAN. The nature of the fault can be diagnosed using a Jaguar approved diagnostic system which reads the fault codes stored in the TCM memory.
Transmission Status Display

The transmission status display is located in a LCD (liquid crystal display) at the top of the instrument cluster, between the
speedometer and the tachometer. The LCD shows the JaguarDrive selector position or the selected gear when in manual 'Jaguar Sequential Shift' mode.
The following table shows the displays and their descriptions.

Symbol Description P Park selected R Reverse selected N Neutral selected D Drive selected S Sport mode selected 1 1st gear selected (manual Jaguar sequential shift mode) 2 2nd gear selected (manual Jaguar sequential shift mode) 3 3rd gear selected (manual Jaguar sequential shift mode) 4 4th gear selected (manual Jaguar sequential shift mode) 5 5th gear selected (manual Jaguar sequential shift mode) 6 6th gear selected (manual Jaguar sequential shift mode) The message center is located in the lower center of the instrument cluster. The message center is a LCD to relay vehicle status and operating information to the driver and can display messages relating to a number of the vehicle systems. If a
transmission fault occurs, the message center will display the message 'GEARBOX FAULT'.

TRANSMISSION CONTROL MODULE

The TCM outputs signals to control the shift control solenoid valve and the EPRS (electronic pressure regulating solenoid) to control the hydraulic operation of the transmission.

The TCM processes signals from the transmission speed and temperature sensors, the ECM and other vehicle systems. From the received signal inputs and pre-programmed data, the module calculates the correct gear, torque converter clutch setting
and optimum pressure settings for gear shift and lock-up clutch control.

The ECM supplies the engine management data over the high speed CAN bus. The TCM requires engine data to efficiently control the transmission operation, for example; flywheel torque, engine speed, accelerator pedal angle, engine temperature.
The steering angle sensor and the ABS (anti-lock brake system) module also supply data to the TCM on the high speed CAN bus. The TCM uses data from these systems to suspend gear changes when the vehicle is cornering and/or the ABS module is controlling braking or traction control.

Using the signal inputs and the memorized data, the TCM control program computes the correct gear and torque converter lock-up clutch setting and the optimum pressure settings for gear shift and lock-up clutch control. Special output-side modules
(power output stages, current regulator circuits), allow the TCM to control the solenoid valves and pressure regulators and consequently precisely control the hydraulics of the automatic transmission. In addition, the amount and duration of engine
interventions are supplied to the engine management by way of the CAN bus.
The transmission has a fully electronic JaguarDrive selector with no Bowden cable connection to the transmission. The
transmission selections are made using a rotary JaguarDrive selector which rises from the floor console once the engine is
running. Rotation of the JaguarDrive selector to any of the five positions is sensed by the TCM via the high speed CAN bus. The TCM then reacts according to the selected position. The 'S' (sport) position selection allows the TCM to operate the transmission using the semi-automatic 'Jaguar Sequential Shift'.

Gear selections are sensed by the TCM when the driver operates the steering wheel paddle switches. Once the JaguarDrive selector position is confirmed, the TCM outputs appropriate information on the high speed CAN bus.
If the JaguarDrive selector is in 'D', 'Jaguar Sequential Shift' is temporary and will cancel after a time period or can be cancelled
by pressing and holding the + paddle for approximately 2 seconds.

If the JaguarDrive selector is in 'S', 'Jaguar Sequential Shift' is permanent and can only be cancelled by pressing and holding
the + paddle for approximately 2 seconds or by moving the JaguarDrive selector to the 'D' position.
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The TCM can be reprogrammed using a Jaguar approved diagnostic system using a flash code. The TCM processor has a 440 kb internal flash memory. Of this capacity, approximately 370 kb are used by the basic transmission program. The remainder,
approximately 70 kb is used to store vehicle-specific application data.

Engine Stall

If the vehicle stalls it will coast down in gear, with the transmission providing drive to the engine. A restart can be attempted
at this point and the engine may start and the driver can continue.

If the coast down speed reduces such that the speed of the engine is less than 600 rev/min, the transmission will go to
neutral, D illumination will flash in the instrument cluster. The driver needs to select neutral or park and then press the brake
pedal to restart the engine.

If the start/stop button is pressed when driving, the message ENGINE STOP BUTTON PRESSED is displayed in the message
center but there will be no change to the ignition state. If the driver requires to switch off the engine, the start/stop button
must be pressed for a second time. The engine will be stopped and will be back driven by the transmission as the vehicle
coasts down. When the engine speed is less than 600 rev/min the transmission engages neutral (flashing D illumination in the
instrument cluster). When vehicle speed is less than 2 km/h (1.2 mph) Park is engaged. The JaguarDrive selector automatically
rotates back to its lowered P position and the vehicle ignition is switched off.

The park engagement is prevented in a stall case as the ignition power is on and D was the last selected gear. The park
engagement speed at ignition off is from the least value of the wheel speeds (CAN signal) and transmission output speed (internal signal).


TRANSMISSION Component Description

The transmission comprises the main casing which houses all of the transmission components. The main casing also
incorporates an integral bell housing.

A fluid pan is attached to the lower face of the main casing and is secured with bolts. The fluid pan is sealed to the main
casing with a gasket. Removal of the fluid pan allows access to the Mechatronic valve block. The fluid pan has a magnet
located around the drain plug which collects any metallic particles present in the transmission fluid.

A fluid filter is located inside the fluid pan. If the transmission fluid becomes contaminated or after any service work, the fluid
pan with integral filter must be replaced.

The integral bell housing provides protection for the torque converter assembly and also provides the attachment for the
gearbox to the engine cylinder block. The torque converter is a non-serviceable assembly which also contains the lock-up clutch
mechanism. The torque converter drives a crescent type pump via drive tangs. The fluid pump is located in the main casing,
behind the torque converter.
The main casing contains the following major components:
Input shaft
Output shaft
Mechatronic valve block which contains the solenoids, speed sensors and the TCM Three rotating multiplate drive clutches
Two fixed multiplate brake clutches
A single planetary gear train and a double planetary gear train.

6 Clutch B 7 Clutch E 8 Brake C 9 Brake D 10 Double planetary gearset 11 Park lock gear 12 Output shaft 13 Park lock pawl 14 Drain plug 15 Magnet 16 Pressure regulator 17 Mechatronic valve block 18 Fluid filter 19 Fluid pan 20 Input shaft 21 Bell housing TORQUE CONVERTER



Item Description 1 Impeller 2 Turbine 3 Stator 4 Freewheel clutch 5 Torque converter hub 6 Stator shaft 7 Turbine shaft

1 Blades 2 Stator held – fluid flow redirected 3 Stator rotates freely 4 Roller 5 Converter at coupling speed 6 Fluid flow from turbine 7 Converter multiplying 8 Fluid flow from impeller 9 Drive from engine 10 Impeller 11 Stator 12 Turbine 13 Output to transmission Fluid emitted from the impeller acts on the turbine. If the turbine is rotating at a slower speed than the fluid from the impeller,
the fluid will be deflected by the turbine blades in the path 'A'. The fluid is directed at and deflected by the stator blades from
path 'B' to path 'C'. This ensures that the fluid is directed back to the pump in the optimum direction. In this condition the
sprag clutch is engaged and the force of the fluid on the stator blades assists the engine in rotating the impeller.

As the rotational speed of the engine and therefore the turbine increases, the direction of the fluid leaving the turbine changes
to path 'D'. The fluid is now directed from the turbine to the opposite side of the stator blades, rotating the stator in the
opposite direction. To prevent the stator from resisting the smooth flow of the fluid from the turbine, the sprag clutch releases,
allowing the stator to rotate freely on its shaft.

When the stator becomes inactive, the torque converter no longer multiplies the engine torque. When the torque converter
reaches this operational condition it ceases to multiply the engine torque and acts solely as a fluid coupling, with the impeller
and the turbine rotating at approximately the same speed.

The stator uses a sprag type, one way, freewheel clutch. When the stator is rotated in a clockwise direction the sprags twist
and are wedged between the inner and outer races. In this condition the sprags transfer the rotation of the outer race to the
inner race which rotates at the same speed. www.JagDocs.com

1 Sprags 2 Inner race 3 Outer race 4 Sprag and cage assembly 5 Sprag outer race 6 Sprag inner race 7 Retaining ring The free wheel clutch can perform three functions; hold the stator stationary, drive the stator and free wheel allowing the
stator to rotate without a drive output. The free wheel clutch used in the ZF 6HP28 transmission is of the sprag type and
comprises an inner and outer race and a sprag and cage assembly. The inner and outer races are pressed into their related
components with which they rotate. The sprag and cage assembly is located between the inner and outer races.

The sprags are located in a cage which is a spring which holds the sprags in the 'wedge' direction and maintains them in
contact with the inner and outer races.

Referring to the illustration, the sprags are designed so that the dimension 'B' is larger than the distance between the inner
and outer race bearing surfaces. When the outer race rotates in a clockwise direction, the sprags twist and the edges across
the dimension 'B' wedge between the races, providing a positive drive through each sprag to the inner race. The dimension 'A'
is smaller than the distance between the inner and outer race bearing surfaces. When the outer race rotates in an
anti-clockwise direction, the dimension 'A' is too small to allow the sprags to wedge between the races, allowing the outer
race to rotate freely.

On the illustration shown, when the outer race is rotated in a clockwise direction, the sprags twist and are 'wedged' between
the inner and outer races. The sprags then transfer the rotation of the outer race to the inner race, which rotates at the same
speed.

Lock-Up Clutch Mechanism

The TCC (torque converter clutch) is hydraulically controlled by an EPRS, which is controlled by the TCM. This allows the torque converter to have three states of operation as follows:
• Fully engaged
• Controlled slip variable engagement
• Fully disengaged.

The TCC is controlled by two hydraulic spool valves located in the valve block. These valves are actuated by pilot pressure supplied via a solenoid valve which is also located in the valve block. The solenoid valve is operated by PWM (pulse width One Way Free Wheel Clutch – Typical

1 Cylinder 2 Baffle plate 3 Ring gear 4 Sun gear 5 Planetary gear spider 6 Torque converter input shaft Torque Converter Input Shaft



Item Description 1 Planetary gear spider 2 Planetary gears (short) 3 Ring gear 4 Output shaft 5 Planetary gear carrier 6 Sunwheel 7 Double planetary gears (long) 8 Sunwheel