1998 JAGUAR X308 valve

Voltage is monitored at the regulators and solenoids for continuity and shorts. For example, when a solenoid is ON the
voltage on the TCM side should be ground , when OFF the voltage should be +12.
Shift Solenoid

The function of the three soleno id valves is to control the flow of transmissi on oil to the various transmission components.
Three solenoid valves are located wi thin the transmission assembly, and are closed when not energized.
Pressure Regulator

The function of the five pressu re regulators is to modulate the oil pressure to the various transmission components. The
regulators are pulse width modulated by the TCM, switching to ground potential. The other side of the regulators being
connected, via an internal TCM relay, to battery voltage. The regulator is closed when not energized by the TCM.
Transmission Fluid Temperature Sensor

Input speed is monitored by the TCM with a rationality check being made against output speed. A fault will be flagged if the
indicated input speed exceeds 7400 rpm. Additionally, a failure judgement will be made if the indicated input speed is <160
rpm with engine speed >608 rpm and output speed >224 rpm
The procedure is similar for the output sp eed diagnostic. A fault (non OBDII) will be flagged if the indicated input speed
exceeds 6712 rpm. Additionally a failure judgement will be ma de if the indicated output speed is <160 rpm and the average
road wheel speed exceeds 100 rpm.
Under normal circumstance s after the output speed diagnost ic fault code has been set, the TCM uses rear wheel speed
information to compute its calculations, this has no effect on transmission operation. However, should a second fault occur,
in the ABS system, thus making rear wheel speed information unavailable, an additional fault code will be logged.
Control Systems
Introduction
Gear selection is achieved by controlling the flow of transmission fluid to internal multi-disc clutches.
The three solenoid valves direct the transmission fluid flow to the selected clutches and the pressure regulators control the
fluid pressure to each component. One pr essure regulator serves as a master pressure control for the entire system and a
second is used exclusively for torque converter clutch lock-up operation.
The TCM controls the internal components thus determining gear selection and shift pattern.
In the event of an electronic system fault the basic function s Park, Reverse Neutral and Drive Fourth are retained by the
hydraulic system.
Transmission Control Module (TCM)

The TCM is located in the same housing as th e ECM and is accessed in the same manner.
The TCM performs several 'self check' procedur es to ensure correct operation. It is possible due to the nature of these faults
that the module will fail to communicate with other nodes. However, condemnation of the TCM should not take place until
any CAN or power supply related problems have been resolved.
There are three self check procedures for the TCM. 1. 1. Check on ROM by calculatin
g a checksum and comparing this with a known stored value.

1.1. The hydraulic system has 'fail-safe' characteristics regardin g 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. 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 me asured variables, ie engine speed, input speed and output speed.
3. 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 through the illumination of the transmission warning lamp.
TCM Inputs
Input Speed Sensor (Torque Converter Turbine)
The input speed sensor provides the TCM with transmission inpu t shaft speed information. This signal is produced from an
inductive pick-up, generating 30 pulses per revolution.
Transmission Output Speed Sensor
The output speed sensor provides the TCM with transmission ou tput shaft speed information. This signal is produced from
an inductive pick-up, generati ng 36 pulses per revolution.
Transmission Oil Temperature Sensor
A thermistor which provides an electrical indication of the oi l temperature to the TCM. The signal is measured as a voltage
with reference to analog ue ground in the TCM.
Kickdown Switch (where fitted)
Kickdown is intended to provide maximum vehicle acceleration , via the appropriate downshift(s), when the operator uses
full throttle. A kickdown switch provides an electrical signal to the TCM wh en the accelerator pedal is fully pressed. The
switch is normally open, connected to vehicle ground. Should the switch fail the TCM will detect kickdown using the
accelerator pedal position.
Throttle Pedal Stop (where fitted)
This component, used where the kickdown switch is not fitted, limits throttle pedal travel .in the same way. The kickdown
feature is retained, but is controlled by throttle position only. The pedal stop must be set, using the PDU, in the same way
as the kickdown switch to optimize performance.
Mode Selection Switch
The mode selection switch is a two position switch indicati ng to the TCM the current performance mode selected by the
driver. The switch generates a tw o-bit digital input to the TCM.
Rotary Position Switch
The rotary position switch detects the position of the transmis sion selector shaft. The switch is supplied as part of a new
transmission assembly, mounted on the transmission body. The swit ch is used to indicate to the TCM the six positions of the shaft: Park, Reverse, Neutral, Drive, Third and Second. The switch provides a four-bit input to the TCM.
Drive to Fourth Switch
Detects the movement of the selector lever from Drive to Fourth position. The selector cable, and therefore the transmission selector shaft, does not move as the lever is operated between these two positions. The switch is located within the 'J-gate'
assembly, producing a digital output to indicate to the TCM that the lever has moved from D to 4 .
Serial Communications Interfaces

Connector Pin Identity Chart for CC014

Connector Pin Identity Chart for EM047
030Shift solenoid valve #1
031Not used
032Shift solenoid valve #3
033Shift solenoid valve #2
034Power ground
035Not used
036Rotary switch L1
037Rotary switch L3
038 to 041Not used
042Input speed sensor (+)
043Not used
044Output speed sensor (-)
045Mode switch Pin A (Normal)
046 to 050Not used
051Pressure regulator #5
053Solenoid valve (+)
052Pressure regulator (+)
054Fused ignition (+)
055Fused ignition (+)
056 to 081Not used
082CAN link In (-)
083CAN link In (+)
084Not used
085CAN link Out (-)
086CAN link Out (+)
087JDS L-line (not used)
088JDS K-line (not used)
Pin NumberCircuit Function
112V ignition
2Security LED (power)
3CAN link In (-)
4CAN link In (+)
5Gate illumination (power)
6Security LED (ground)
7Not used
8CAN link Out (-)
9CAN link Out (+)
10Gate illumination (ground)
11Not used
12Not used

Connector Pin Identity Chart for EM046



Pin NumberCircuit Function
00APosition L1
00BPosition L2
00CPosition L3
00DPosition L4
00EDigital ground
00FNot used
00GNot used
00HNot used
00JB+
00KPark and neutral switch
Pin NumberCircuit Function
001Output speed sensor (+)
002Pressure regulator #1
003Pressure regulator #2
004Shift solenoid valve #3
005Input speed sensor (+)
006Input speed sensor (-)
007Pressure regulator #3
008Shift solenoid valve #1
009Shift solenoid valve #2
010Output speed sensor (-)
011Pressure regulator #4
012Shift solenoid valves (+)
013Analogue ground
014Fluid temperature sensor
015Pressure regulator #5
016Pressure regulators (+)

Automatic Transmission/Transaxle - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26
- Electronic Pressure Control (EPC) Solenoid
In-vehicle Repair
Removal

1. Disconnect battery ground cable.
Remove the battery cover.

2. Raise the vehicle on a suitable lift.
2. WARNING: TRANSMISSION FLUID MAY CAUSE
SEVERE BURNS, ENSURE THAT ALL SAFETY PROCEDURES
ARE OBSERVED.
Carefully remove the drain plug and drain the
transmission fluid.

3. Remove the twenty-two fixings which secure the fluid pan .
Remove the fluid pan and all traces of gasket material.

4. Disconnect regulator / solenoid connectors.
5. Remove RH rear valve body securing screws.

Installation


6. Remove the nine screws from th e pressure regulator / solenoid
retaining plate.

7. Remove the relevant pressure regulator.

1. Installation is the reverse of the removal procedure, noting
that a new pressure regulator 'O' ring MUST be used.
Fit the nine screws securing the pressure regulator /
solenoid retaining plate and ti ghten to the specified torque
figure.
2. Refit the RH rear valve body secu ring screws and tighten to the
specified torque figure.

Automatic Transmission/Transaxle - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26
- Main Control Valve Body
In-vehicle Repair
Removal

1. Disconnect battery ground cable.
Remove the battery cover.

2. Raise the vehicle for access.
2. WARNING: TRANSMISSION FLUID MAY CAUSE
SEVERE BURNS, ENSURE THAT ALL SAFETY PROCEDURES
ARE OBSERVED.
Carefully remove the drain plug and drain the
transmission fluid.

3. Remove the twenty-two bolts which secure the fluid pan.
Remove the fluid pan and all tr aces of gasket material.
4. Remove the fluid filter, (44.24.07).

5. Remove the input speed sensor.
• NOTE: M5 fixing.
1. Remove the screw from the input speed sensor securing bracket and pu ll the sensor clear.
Disconnect the harness multiplug.