Automatic Transmission/transaxle: Other Jaguar XJ X351

CONTROL DIAGRAM

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

POWER FLOWS

Operation of the transmission is controlled by the transmission control module (TCM), which electrically activates various solenoids to control the transmission gear selection. The sequence of solenoid activation is based on programmed information in the transmission control module (TCM) memory and physical transmission operating conditions such as vehicle speed, throttle position, engine load and JaguarDrive selector position.

Engine torque is transferred, via operation of single or combinations of clutches to the 2 planetary gear trains. Both gear trains are controlled by reactionary inputs from brake clutches to produce the 6 forward gears and 1 reverse gear. The ratios are as follows

Shift Elements

The shift elements are three rotating multiplate clutches (A, B and E) and two fixed multiplate brakes (C and D). All shifts from 1st to 6th gears are power-on overlapping shifts. Overlapping shifts can be described as one of the clutches continuing to transmit drive at a lower main pressure until the next required clutch is able to accept the input torque.

The shift elements, clutches and brakes are actuated hydraulically. Fluid pressure is applied to the required clutch and/or brake, pressing the plates together and allowing drive to be transmitted through the plates. The purpose of the shift elements is to perform power-on shifts with no interruption to traction and smooth transition between gear ratios.

Power Flow 1st Gear

The JaguarDrive selector and the selector valve spool 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.

The double web planetary gear train is locked against the transmission housing by brake 'D'. This allows ring gear 2 (output shaft) to be driven in the same direction as the engine via the long planetary gears.

Note. Refer to 'Shift Elements' illustration for key

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

Power Flow 3rd 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 driven via clutch 'B' which is engaged. The long planetary gears, which are also meshed with the short planetary gears, cannot roll around the fixed sunwheel 2 and therefore transmit drive to the locked double web planetary gear train carrier in the direction of engine rotation.

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 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 gears.

The long planetary gears, which are also 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 6th 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'.

Clutches 'A' and 'B' are released, removing the effect of the single web planetary gear train.

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 clutch 'B'.

With clutch 'B' applied, sunwheel 2 in the double web planetary gear train is driven and meshes with the long planetary gears.

The double web planetary gear carrier is locked to the transmission housing by brake clutch 'D'. This allows ring gear 2 to be driven in the opposite direction to engine rotation by the long planetary gears.

Note. Refer to 'Shift Elements' illustration for key

INSTRUMENT CLUSTER

Instrument Cluster in Standard Mode

The instrument cluster is connected to the transmission control module (TCM) via the high speed controller area network (CAN) bus. Transmission status is transmitted by the transmission control module (TCM) and displayed to the driver in the instrument cluster. Refer to Instrument Cluster information.

Malfunction Indicator Lamp

Transmission related faults that effect the vehicle emissions output will illuminate the malfunction indicator lamp (MIL). The malfunction indicator lamp (MIL) is illuminated by the engine control module (ECM) on receipt of a relevant fault message from the transmission control module (TCM) on the high speed controller area network (CAN). The nature of the fault can be diagnosed using a Jaguar approved diagnostic system, which reads the fault codes stored in the transmission control module (TCM) memory.

Transmission Status Display

The transmission status display is located in the tachometer. The display shows the JaguarDrive selector position. When the transmission is in the Jaguar sequential shift mode the current gear is displayed in the information window.

Message Center

The right side of the instrument cluster, which normally shows the tachometer, changes to a message center to display warnings and temporary alerts. If a transmission fault occurs, the message center will display the message 'GEARBOX FAULT'.

Instrument Cluster in Dynamic Mode

Scheme 45

Gearshift Points

When the transmission is in the Jaguar sequential shift mode, the appearance of the instrument cluster changes to the dynamic mode and the current gear is displayed in the information window.

TRANSMISSION CONTROL MODULE

The transmission control module (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 transmission control module (TCM) processes signals from the transmission speed and temperature sensors, the engine control module (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 engine control module (ECM) supplies the engine management data over the high speed controller area network (CAN) bus. The transmission control module (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 anti-lock brake system (ABS) module also supply data to the transmission control module (TCM) on the high speed controller area network (CAN) bus. The transmission control module (TCM) uses data from these systems to suspend gear changes when the vehicle is cornering and/or the anti-lock brake system (ABS) module is controlling braking or traction control.

Using the signal inputs and the memorized data, the transmission control module (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 transmission control module (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 controller area network (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 transmission control module (TCM) via the high speed controller area network (CAN) bus. The transmission control module (TCM) then reacts according to the selected position. The 'S' (sport) position selection allows the transmission control module (TCM) to operate the transmission using the semi-automatic 'Jaguar Sequential Shift'.

Gear selections are sensed by the transmission control module (TCM) when the driver operates the steering wheel paddle switches. Once the JaguarDrive selector position is confirmed, the transmission control module (TCM) outputs appropriate information on the high speed controller area network (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.

The transmission control module (TCM) can be reprogrammed using a Jaguar approved diagnostic system using a flash code. The transmission control module (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 (controller area network (CAN) signal) and transmission output speed (internal signal).

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

1. Input shaft
2. Output shaft
3. Mechatronic valve block which contains the solenoids, speed sensors and the transmission control module (TCM)
4. Three rotating multiplate drive clutches
5. Two fixed multiplate brake clutches
6. A single planetary gear train and a double planetary gear train.

MECHATRONIC VALVE BLOCK

The Mechatronic valve block is located in the bottom of the transmission and is covered by the fluid pan. The valve block houses the transmission control module (TCM), electrical actuators, speed sensors and control valves which provide all electro-hydraulic control for all transmission functions. The Mechatronic valve block comprises the following components

1. Transmission control module (TCM)
2. Pressure regulator solenoids
3. Shift control solenoid
4. Damper
5. Hydraulic spool valves
6. Selector valve
7. Temperature sensor
8. Turbine speed sensor
9. Output shaft speed sensor.

Sensors

Speed Sensors

The turbine speed sensor and the output shaft speed sensor are Hall effect type sensors located in the Mechatronic valve block and are not serviceable items. The transmission control module (TCM) monitors the signals from each sensor to determine the input (turbine) speed and the output shaft speed.

The turbine speed is monitored by the transmission control module (TCM) to calculate the slip of the torque converter clutch and internal clutch slip. This signal allows the transmission control module (TCM) to accurately control the slip timing during shifts and adjust clutch application or release pressure for overlap shift control.

The output shaft speed is monitored by the transmission control module (TCM) and compared to engine speed signals received on the controller area network (CAN) bus from the engine control module (ECM). Using a comparison of the two signals the transmission control module (TCM) calculates the transmission slip ratio for plausibility and maintains adaptive pressure control.

Temperature Sensor

The temperature sensor is also located in the Mechatronic valve block. The transmission control module (TCM) uses the temperature sensor signals to determine the temperature of the transmission fluid. These signals are used by the transmission control module (TCM) to control the transmission operation to promote faster warm-up in cold conditions or to assist with fluid cooling by controlling the transmission operation when high fluid temperatures are experienced. If the sensor fails, the transmission control module (TCM) will use a default value and a fault code will be stored in the transmission control module (TCM).

Damper

There is one damper located in the valve housing. The damper is used to regulate and dampen the regulated pressure supplied via EPRS. The damper is load dependent through modulation of the damper against return spring pressure.

The damper comprises a piston, a housing bore and a spring. The piston is subject to the pressure applied by the spring. The bore has a connecting port to the function to which it applies. Fluid pressure applied to the applicable component (i.e. a clutch) is also subjected to the full area of the piston, which moves against the opposing force applied by the spring. The movement of the piston creates an action similar to a shock absorber, momentarily delaying the build up of pressure in the circuit. This results in a more gradual application of clutches improving shift quality.

Spool Valves

The valve block spool valves control various functions of the transmission. The spool valves are of conventional design and are operated by fluid pressure.

Each spool valve is located in its spool bore and held in a default (unpressurized) position by a spring. The spool bore has a number of ports which allow fluid to flow to other valves and clutches to enable transmission operation. Each spool has a piston which is waisted to allow fluid to be diverted into the applicable ports when the valve is operated.

When fluid pressure moves a spool, one or more ports in the spool bore are covered or uncovered. Fluid is prevented from flowing or is allowed to flow around the applicable waisted area of the spool and into another uncovered port. The fluid is either passed through galleries to actuate another spool, operate a clutch or is returned to the fluid pan.

DRIVE CLUTCHES

Multiplate Drive or Brake Clutch - Typical

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 supercharger (SC) and 3.0L diesel models, the updated 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

1. Sunwheel
2. Three (naturally aspirated versions) or four (5.0L supercharger (SC) and 3.0L diesel versions) planetary gears
3. Planetary gear carrier (spider)
4. Ring gear or annulus.

Torque Converter Input Shaft

The double planetary gear train comprises

1. Two sunwheels
2. Three short planetary gears
3. Three long planetary gears
4. Planetary gear carrier
5. Ring gear or annulus

ELECTRONIC PARK LOCK

The park lock is electronically actuated by solenoid valve located in the valve block. The park lock is engaged by a mechanical spring system comprising a parking disc and a lock cylinder controlled by a solenoid valve.

The park lock is engaged when the transmission control module (TCM) receives a park request from the JaguarDrive selector. When the park lock is released, a solenoid valve in the valve housing directs hydraulic pressure to the lock cylinder, which moves the piston within the cylinder and releases the park lock pawl at the rear of the transmission by means of a connecting rod. The solenoid on the lock cylinder is energized and locks the cylinder piston in the unlocked position. Additional locking of the piston is achieved with ball catches within the lock cylinder.

When park is selected, the solenoid on the lock cylinder is de-energized, the ball catches are released and the piston is free to move in the lock cylinder. The solenoid in the valve housing is also de-energized. The spring loaded parking disc pulls the cylinder piston in the park direction which allows the park disc to move on its mounting. This movement is transferred via the connecting rod to parking pawl, which is engaged in the park lock gear.

If an electrical failure occurs, the park lock can be manually released by means of an emergency park release lever located in the floor console. The lever is connected to the parking disc by a cable and allows the park lock to be released manually. Refer to: External Controls (307-05, Description and Operation).

The transmission control module (TCM) is an integral part of the Mechatronic valve block which is located at the bottom of the transmission, within the fluid pan. The transmission control module (TCM) is the main controlling component of the transmission.

The transmission control module (TCM) processes signals from the transmission speed and temperature sensors, engine control module (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.

CHECK

Note. Some variation in the illustrations may occur, but the essential information is always correct.

Scheme 46

1. The following steps must be observed before starting the transmission fluid level check. The vehicle must be on a horizontal ramp. The parking brake must be applied. The engine must be running for 2 minutes with the transmission control switch (TCS) in the "P" position.
2. Connect the diagnostic tool to the vehicle.
3. Start the engine. Apply, and hold, the footbrake. Move the selector lever from 'P' through all gear positions, pausing in each gear position for 2-3 seconds and return to the 'P' position.
4. Raise and support the vehicle.
5. Refer to «Air Deflector»(ref-570100-S33802335332013080600000) information.
6. Place a suitable container under the transmission fluid fill plug.
7. Special Tool(s): 307-452 Clean the area around the transmission fluid level plug.

INPUT SHAFT SEAL

Special Tool(s)

100-012 Slide Hammer 100-012-01 Slide Hammer Adapter 307-613 Holding Pins, Torque Converter 308-246 Installer, Front Seal 308-375 Remover, Input and Output Seal

Scheme 47

Scheme 48

EXTENSION HOUSING SEAL

Special Tool(s)

100-012 Slide Hammer 100-012-01 Slide Hammer Adapter 204-264 Pinion Seal Replacer 205-053 Retainer, Drive Flange 303-D121 Puller, General Purpose 308-375 Remover, Input and Output Seal

TRANSMISSION V8 5.0L PETROL / V8 S/C 5.0L PETROL

Note. Some variation in the illustrations may occur, but the essential information is always correct.

Note. Some illustrations may show the transmission removed for clarity.

1. Refer to «Battery Disconnect And Connect»(ref-570102-S06137827622013080600000) information.
2. Raise and support the vehicle.
3. Refer to «Exhaust System»(ref-570143-S05033493582013080600000) information.
4. Make sure that the alignment mark is visible through the inspection hole on removal of the last torque converter bolt.
5. Make sure that the alignment mark is visible through the inspection hole on removal of the last torque converter bolt.
6. Using a suitable stand, support the transmission.
7. Make sure that the transmission is secured with suitable retaining straps.
8. Lower the rear of the transmission for access.
9. Install the torque converter retainer.

Note. Some variation in the illustrations may occur, but the essential information is always correct.

Note. Some illustrations may show the transmission removed for clarity.

Scheme 49

1. Raise the powertrain assembly jack and transmission assembly.
2. Torque: 48 Nm
3. Torque: 48 Nm
4. Torque: 48 Nm
5. Torque: 45 Nm
6. Remove the support.
7. Torque: 127 Nm
8. Torque: 63 Nm
9. Torque: 10 Nm
10. Torque: 10 Nm
11. Refer to «Exhaust System»(ref-570143-S05033493582013080600000) information.
12. Refer to «Battery Disconnect And Connect»(ref-570102-S06137827622013080600000) information.