1998 JAGUAR X308 cooling system

3.3. Gradient: Under specific speeds and loads
4. 4. Cruise: During cruise control
5. 5. Manual: Shift map when the LH side of the 'J gate' is used
Three specific condition shift maps have a higher priority than the two base shift maps and will intervene when appropriate
conditions prevail for traction, gradient or cruise.
When traction control (engine or brake system derived) is operational the TCM will implement the traction map to maximise
control of wheel slip.
The gradient maps are intended to enhance vehicle drivability when towing or climbing a gradient. The TCM will implement
the maps when increased driving resistan ce is detected and enhanced drivability, cooling and increa sed performance is
appropriate.
The cruise map is intended to minimize unwanted gearshifts and 'hunting' and is activated when cruising near to the set
speed, or resuming.
Connector Pins Identification
Connector Pin Identity Chart for EM007

Pin NumberCircuit Function
001Pressure regulator 2
002Mode switch status
003Not used
004Pressure regulator #4
005Pressure regulator #1
006Power ground
007Not used
008Rotary switch L2
009Rotary switch L4
010 to 011Not used
012Mode switch Pin B (Sport)
013D to 4 switch
014Input speed sensor (-)
015Output speed sensor (screen)
016Output speed sensor (+)
017Not used
018Kickdown switch (where used)
019 to 020Not used
021Analogue ground
022Fluid temperature sensor
023Input speed sensor (screen)
024 to 025Not used
026B+
027Not used
028Digital ground
029Pressure regulator #3

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 manu ally 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 manu ally 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; th e 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 auto matically modify the Normal or Sports shift map to enhance
the operation of the vehicle:
1. 1. Traction: When traction intervention is active.
2. 2. Hot mode: Extreme engine/transmission temperatures.
3. 3. Gradient: Under specific speeds and loads.
4. 4. Manual: Driver initiated override of the normal shif t map when the LH side of the 'J gate' is used.
Traction
When traction or stability control (engine or brake system de rived) is operational the TCM will implement the traction map
to maximize control of wheel slip.
Gradient
The gradient function is intended to enhance vehicle drivea bility when climbing a gradient or towing. The TCM will
implement the function when increased driving resistance is de tected, and provides enhanced driveability, additional cooling

Transmission/Transaxle Cooling - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26 -
Transmission Cooling
Description and Operation
The transmission fluid cooling system maintains fluid temperature within specified limits.

Parts List
Component Descriptions
The transmission fluid pipes:
Transfer fluid from the transmission to the cooler under the action of the hydraulic system pump. Return the cooled fluid from th e cooler to the transmission.
The transmission fluid cooler:
Is a plate type made from aluminum. Is mounted in the engi ne cooling radiator right-hand end tank.
Overheating Protection
If the engine coolant or transm ission fluid temperatures exceed their predefined limits, th e transmission control module locks
the torque converter clutch. By reducing slip, this minimises th e amount of heat transferred to the engine cooling system from
the transmission fluid.

ItemPart NumberDescription
1—Fluid pipe, oil FROM cooler
2—Fluid pipe, oil TO cooler

Transmission/Transaxle Cooling - 4.0L SC V8 - AJ26 - Transmission
Cooling
Description and Operation
The transmission fluid cooling system maintains the fluid temperature within specified limits. The cooling element is located
in the engine cooling radiator LH end tank.
Fluid is circulated, under pressure, by the transmission pump to the cooler.
General Layout

Overheating Protection
If the engine coolant or transmission fluid temperatures exceed their predefined limits, the transmission control module
locks the torque converter clutch . By reducing slip, this minimises the amount of heat transferred to the engine cooling
system from the transmission fluid.

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to B2
B2: CHECK FOR LOW EX HAUST TEMPERATURE
Check the engine and exhaust system for normal running
temperature 1
Is the engine and exhaust sy stem up to normal running
temperature?
Yes GO to B3
No Rectify possible leaking exhaust manifold / catalyst, general
causes of an over rich mixture and engine cooling system
operation. Test the system for correct operation.
GO to B8
B3: CHECK FOR O2 SENS OR HEATER CONTINUITY
Ignition switch to position 0 1
Disconnect EM021
Bracket on top of gearbox or Bulkhead rear of engine
2
With EM021 disconnected, measure the resistance between
EM021/001 and EM021/002. 3
Is the resistance between 4 and 10 OHM?
Yes
GO to B4
No Renew O2 sensor, reconnect plug(s).
GO to B8
B4: CHECK FOR O2 SENSOR FAILURE

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to D2
D2: CHECK FOR LOW EXHAUST TEMPERATURE
Check the engine and exhaust system for correct operation
and normal running temperature 1
Is the engine and exhaust system operating correctly and up to
normal running temperature?
Yes GO to D3
No Rectify leaking exhaust manifold / catalyst, general causes of
an over rich mixture and engine cooling system operation
and test the system for correct operation.
GO to D7
D3: CHECK FOR O2 SENSOR FAILURE
Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
Measure the voltage between EM022/001 and EM022/002. 2

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to F2
F2: CHECK FOR LOW EXHAUST TEMPERATURE
Check the engine and exhaust system for normal running
temperature 1
Is the engine and exhaust sy stem up to normal running
temperature?
Yes GO to F3
No Rectify possible leaking exhaust manifold / catalyst,
general causes of an over ri ch mixture and engine cooling
system operation. Test the sy stem for correct operation.
GO to F8
F3: CHECK FOR O2 SENSOR HEATER CONTINUITY
Ignition switch to position 0 1
Disconnect EM023
Bracket on top of gearbox or Bulkhead rear of engine
2
Measure the resistance between EM023/001 and
EM023/002. 3
Is the resistance between 4 and 10 OHM?
Yes
GO to F4
No Renew O2 sensor. Reconnect plug(s).
GO to F8
F4: CHECK FOR O2 SENSOR FAILURE

Conne
ct the scan tool
1
Have the DTC(s) and fr

eeze
frame data been recorded?
Yes GO to H2
H2: CHECK
FOR LOW EXHAUST TEMPERATURE
Chec

k the engine and exhaust
system for correct operation
and normal running temperature
1
Is th
e engine and exhaust system operating correctly and up to
normal running temperature?
Yes GO to H3
No Rectify leaking exhaust manifold / catalyst, general causes of
an over rich mixture and engine cooling system operation and
test the system for correct operation.
GO to H7
H
3: CHECK FOR O2 SENSOR FAILURE
I

gnition switch to position 0
1
Di

sconnect EM024
Bracket on top o

f gearbox or
Bulkhead rear of engine
2
R
un the engine for a period to
warm the sensor and then
maintain a steady speed of approximately 2500 rpm.
3
W
ith EM024 disconnected, measure the voltage between
EM024/001 and EM024/002.
4
Is
the voltage between 600mV and 1.0 Volt?
Yes GO to H4
No Renew O2 sensor. Reconnect plug(s).
GO to H7
H
4: CHECK FOR O2 SENSOR FAILURE