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General Information & Servicing: Other Jaguar XKR I

Automatic Trans 18 illustrations ~1838 words

Transmission Casing

  1. Stator, intermediate and output shafts.
  2. Three epicyclic geartrain.
  3. Six multi-disc clutch/brake packs.
  4. Two freewheels (One-way clutches).
  5. Hydraulic pump.
  6. Parking lock assembly.
  7. Electro-hydraulic control unit.
  8. Internal harness and 13 pin connector with bayonet lock.

Hydraulic Pump

  1. This engine driven pump is located at the front of the transmission casing and provides pressure for the hydraulic functions.
  2. Supplies fluid under pressure to the torque converter, geartrain, electro-hydraulic control unit and the lubrication circuit.
  3. Draws fluid from the fluid pan below the transmission casing, through a filter.

Parking Lock

This component prevents movement of the vehicle by engaging a fixed pawl with the parking lock gear located on the output shaft. The pawl is engaged by moving the gear selector lever to the park (P) position.

Electro-Hydraulic Control Unit

This unit, mounted in the transmission lower case, converts signals, mechanical from the J-gate and electrical from the TCM, into hydraulic functions.

The following components are assembled to the unit

  1. Selector valve.
  2. Shift plate.
  3. Control valve - modulating pressure.
  4. Control valve - shift pressure.
  5. Solenoid valve 1 <-> 2 and 4 <-> 5 shift.
  6. Solenoid valve 3 <-> 4 shift.
  7. Solenoid valve 2 <-> 3 shift.
  8. Solenoid valve - converter lock-up.
  9. Speed sensors (2).
  10. Temperature sensor.

Speed Sensors

There are two speed sensors within the transmission assembly which provide input to the TCM. These inputs, when used in conjunction with CAN data relative to engine speed (from ECM) and road speed (from ABS), are used to electronically control the transmission.

Temperature Sensor

The output from this sensor allows the TCM to compensate for the affect of fluid temperature on shift time and quality

Hydraulic Control

The selector valve is operated directly by the J-gate and directs fluid flow for P R N D .

Of the four solenoid valves, 3 control shifts and 1 controls converter lock-up. One control valve controls modulating pressure and the other shift pressure.

Regulating valves are used to maintain/control pressure for lubrication, normal operating functions, and the supply to the control valves and shift valves.

In the event of a system fault, the TCM will adopt "limp home" mode.

Electrical Control

Refer to TRANSMISSION CONTROL MODULE (TCM) .

TRANSMISSION CONTROL MODULE (TCM)

The TCM controls the transmission internal components thus determining gear selection and shift pattern.

Scheme 33

Scheme 33: TRANSMISSION CONTROL MODULE (TCM)
Scheme 33: TRANSMISSION CONTROL MODULE (TCM)

The TCM is located in the same housing as the engine control module (ECM) and is accessed in the same manner. With the two connectors unplugged the TCM may be withdrawn, complete with mounting bracket. The mounting bracket is secured to the TCM by 2 lock nuts.

Input Signals

  1. Gear selector position (Dual Linear Switch).
  2. Transmission oil temperature.
  3. Kickdown.
  4. Speed sensor #1.
  5. Speed sensor #2.
  6. Mode switch

CAN Input Signals

  1. Traction status.
  2. ABS malfunction.
  3. ABS status.
  4. Engine torque status.
  5. Throttle position.
  6. Accelerator pedal position.
  7. Engine torque reduction confirmation.
  8. Engine speed.
  9. Engine coolant temperature.
  10. Cruise status.
  11. OBD-II fault code clear request.
  12. Throttle malfunction warning RED or AMBER.
  13. All road wheel speeds.
  14. Token for network status ECM.
  15. Token for network status INST.
  16. Token for network status ABS.
  17. Diagnostic data in from external device (PDU).

Output Signals

  1. Solenoid valve 1 <-> 2 and 4 <-> 5 shift.
  2. Solenoid valve 2 <-> 3 shift.
  3. Solenoid valve 3 <-> 4 shift.
  4. Solenoid valve converter lock-up clutch.
  5. Control valve - modulating pressure.
  6. Control valve - shift pressure.

CAN Output Signals

  1. Engine torque reduction request.
  2. MIL status (whether present DTC should operate MIL).
  3. Transmission input speed.
  4. Transmission output speed.
  5. Converter slip.
  6. Kickdown status.
  7. Gear position (actual).
  8. Gear position (selected).
  9. Gear selection fault.
  10. Converter lock-up status.
  11. Current selected shift map.
  12. Transmission oil temperature.
  13. Transmission malfunction.
  14. Pecus flag (state of current TCM program).
  15. Target for next gear position.
  16. Gear shift torque transfer progress at shift.
  17. MIL status (response to activate the MIL relevant to a DTC).
  18. OBD-II fault code clear acknowledgment.
  19. Transmission DTCs (P codes).
  20. Token for network status TCM.
  21. Diagnostic data out to external device (PDU).

Emergency Running (electronic Limp-Home Mode)

The TCM constantly monitors the transmission for faults. In the event of a problem the TCM will adopt the limp-home mode, in which the gear currently held remains engaged, until P is selected. The modulating and shift pressures will increase to maximum and converter lock-up will be inhibited.

Following the selection of "P" , the only ratios available will be 2 (irrespective of forward ratio manual selection) and "R".

With the vehicle at rest, the procedure to manually select is as follows

  1. Select "P".
  2. Switch OFF the ignition.
  3. Wait 10 seconds.
  4. Start the engine.
  5. Select "R" (reverse will be selected).
  6. Select "D" (2 will be selected).

The limp-home mode will be retained until the fault is remedied or the fault code has been erased. Intermittent faults may be cleared by cycling the ignition OFF/ON. In certain cases the component may need to be operated before the fault code is cleared eg. a shift solenoid.

Emergency Running (Mechanical/Hydraulic Limp-Home Mode)

Should slip be detected, due to a mechanical failure or loss of pressure, the transmission will either shift to, and hold 3 or shift to, and hold, the last gear which was known to be all right. This condition may be cleared by cycling the ignition OFF/ON following mechanical repair.

The operator will be made aware of certain faults by a warning message on the instrument cluster.

Data concerning OBD-II related transmission failures is stored in the ECM for access via the J1962 socket.

Safety Functions

These functions are designed to safeguard against inappropriate actions by the operator as well as system malfunctions.

The electrical and diagnostic system has been designed such that system integrity is protected at all times, the safety concept being based on the following three points.

  1. The hydraulic system has "fail-safe" characteristics regarding its electrical operation, such that should the power supply be lost to the electro-hydraulic actuators the transmission will initiate a limp-home mode.
  2. Recognition of critical shift operation by monitoring the last element in the signal path, ie the solenoid valve, and checking by means of redundant measured variables relative to engine, transmission and road speeds.
  3. Each time the vehicle is started there is a check on the entire safety hardware and the associated program parts and signal paths. A malfunction in this part of the system, or triggering of the safety circuit, is communicated to the operator by a warning message on the instrument cluster.
CAUTIONDo not engage "R" or "P" with the vehicle in motion.

Should "R" be engaged with the vehicle in forward motion, the transmission will default to neutral until either the vehicle speed decreases to 4 mph or "D" is selected.

Towing

The vehicle may be towed provided that

  1. Selector in position "N".
  2. Speed < 50 kph.
  3. Distance < 50 km.

Scheme 34

Scheme 34: "J" Gate Layout
Scheme 34: "J" Gate Layout

Range Selection

The "J" gate selector lever is connected to the transmission via a cable which operates the transmission selector shaft between positions P R N D only. The shift lever disconnects from the cable when the lever is moved across the gate from "D" to 4 .

Movement of the lever between P R N D manually controls the flow of transmission fluid, the TCM having control of the forward gear selected in "D".

Movement of the lever to 4, 3 and 2 positions does not manually modify the fluid flow, the TCM detects these positions using the DLS and controls the ratios electronically by energizing solenoids.

Shift Point Control

The gearshift points are controlled by the TCM, as a function of the output speed, engine load, engine speed, selector position and shift program selected. The operator has control over the shift points via the shift lever, throttle pedal movement, kickdown function and mode switch.

Mode Switch

This switch allows operator selection of two base shift modes; Normal and Sport; the switch being illuminated when Sport is selected. This function alters the values in the TCM shift point calculations.

Shift Programs

Upon encountering the following conditions, the TCM will automatically modify the Normal or Sports shift map to enhance the operation of the vehicle

  1. Traction: When traction intervention is active.
  2. Hot mode: Extreme engine/transmission temperatures.
  3. Gradient: Under specific speeds and loads.
  4. Manual: Driver initiated override of the normal shift map when the LH side of the "J" gate is used.

Traction

When traction or stability control (engine or brake system derived) is operational the TCM will implement the traction map to maximize control of wheel slip.

Gradient

The gradient function is intended to enhance vehicle driveability when climbing a gradient or towing. The TCM will implement the function when increased driving resistance is detected, and provides enhanced driveability, additional cooling and/or increased performance as appropriate.

Controller Area Network (CAN)

The TCM is an integral part of the CAN system which facilitates the interchange of real-time data between control modules and sensors.

Transmission Pressure Regulators & Shift Solenoids Circuit Diagram

For 2001 models, see TRANSMISSION .

For 2002 models, see TRANSMISSION .

Speed Sensor/TCM Circuit Diagram

For 2001 models, see TRANSMISSION .

For 2002 models, see TRANSMISSION .

Scheme 35

Scheme 35: CONNECTOR IDENTIFICATION
Scheme 35: CONNECTOR IDENTIFICATION

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Scheme 40

Scheme 40: Special Tools
Scheme 40: Special Tools

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Scheme 42: Removal
Scheme 42: Removal

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Scheme 47
Scheme 47
  1. Remove battery cover and disconnect ground cable from battery terminal. Refer to «BATTERY DISCONNECTION PROCEDURE»(ref-171253-S19302448882005020100000) .
  2. Select "N" and chock the road wheels.
  3. Remove front muffler. Slacken the muffler to catalytic converter securing clamps (left- and right-hand sides). Slacken the front to intermediate muffler securing clamps (left - and right-hand sides). Disconnect the front muffler from the intermediate mufflers and then from the downpipe catalytic converters.
  4. Remove the engine rear mounting bracket. Support the transmission. Remove the bolt, engine rear mounting to transmission. Remove the four bolts which secure the mounting cross member to the body.
  5. Detach the driveshaft from the transmission drive flange. If the transmission is to be refitted, mark the position of the coupling to drive flange. CAUTION: Under no circumstances remove the driveshaft to flexible coupling fixings. Remove the transmission drive flange to flexible coupling three fixings.
  6. Secure the driveshaft wrench 205-053 to the output shaft flange.
  7. Remove the output shaft flange. Using a suitable tool, relieve the "staked" portion from the output shaft keyway. Remove and discard the flange nut using a suitable socket and resisting rotation with special tool 205-053. Check the flange seal diameter for damage and renew if necessary.
  8. Using a suitable seal puller, remove the housing oil seal.

Scheme 48

Scheme 48: Installation
Scheme 48: Installation

Scheme 49

Scheme 49
Scheme 49

Scheme 50

Scheme 50
Scheme 50
  1. Installation is the reverse of the removal procedure noting the following
  2. Fit the oil seal. Lubricate the housing seal bore. Lubricate the outside diameter of the seal. Using seal replacer 307-378 drive the seal squarely into position.
  3. Refit the drive flange. Use a new nut. Tighten the flange nut to the specified torque figure. Stake the nut to the output shaft.
  4. Refit the bolts securing the driveshaft and tighten to the specified torque figure. (Scheme 48)
  5. Refit the rear mounting crossmember and tighten the securing bolts to the specified torque figures.
  6. Perform the «BATTERY RECONNECTION PROCEDURE»(ref-171253-S14708357522005020100000).
  7. Refill transmission. Refer to «TRANSMISSION FLUID FILLING»(ref-171810-S18870355362005021400000).
  8. Check for leaks and remove spilled fluid.

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