1994 JAGUAR XJ brake

ZF Automatic Transmissions Service Manual
The torque converter acts in all four forward gears and in reverse. The converter lock-up clutch closes in 4th gear at
a point depending on road speed and accelerator position; engine power is then transmitted by purely mechanical
means.
A low-loss oil pump in the front of the transmission housing supplies the converter, the automatic gear shift and the
lubrication circuit; oil is drawn from a sump in the bottom of the gear train housing through a filter. The pump drive
gear is keyed to the converter impeller hub and therefore turns when the engine is running, thereby pressurizing the
oil.
Selected ratios
Di, 31, 21
1.1.2 Four-speed Epicychc Gear Train
The torque converter drives a mechanical epicyclic gear train providing four forward ratios and reverse. Individual ra-
tios are obtained by coupling togetherthevarious parts of the geartrain by means of hydraulically actuated multi-disc
clutches and brakes; built in freewheels permit gear shifts without any interruption of the power flow. Operation of the
clutches and gear sets is described
in sub-section 1.1.3.
Each epicyclic (or planetary) gear set comprises a central, sungear, an annulus and a planetary carrier which supports
four small planet gears or pinions. Two gear sets are used in this transmission. A compound gear set comprising front
annulus and planet carrier, rear annulus and planet carrier and a common sungear transmits the drive
in all gears ex- cept REVERSE; a single planetary carrier, annulus and sungear transmits the fourth gear drive. The table below shows
the resulting clutch operation
in the selected gear ratios.
Resulting clutch operation
A Clutch drives annulus clockwise
E Clutch
& OWC drives output shaft clockwise
D2,32,22
D3,33, 23
04
R
Park, Neutral
A Clutch drives annulus clockwise
C1 Clutch holds sungear against anti-clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch & OWC holds sungear against anti-clockwise
B Clutch drives sungear clockwise
D Clutch holds carrier against clockwise
E Clutch
& OWC drives output shaft anti-clockwise
E Clutch
& OWC applied (hydraulics)
OWC = one way clutch
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1.1.6 Gearshift Selection
Gearshift selection is by movement of the shift lever which through a selector cable causes repositioning ofthe manual
(selector) valve to direct oil pressure to the required shift valve. The automatic shift points are determined by acceler- ator position and road speed: throttle movement moves a cam on the throttle valve, directing oil pressure to the shift
valves and modulator valve, road speed modulates hydraulic pressure through a centrifugal governor driven by the
transmission output shaft. Operation
of the hydraulic control system is shown diagrammatically in the circuit dia
-
grams on the following pages.
I I
I
I
2 -3- I
I I
I
I
- I
I I 1 4 -5 - - -
+ ! + I I 'I 10 I I
I
I 1
1, 1-Y I
I I
I
I
1. Engine 8. Pump regulator valve 2. Torque converter 9. Damper
3. Pump 10. Governor valve 4. Clutch & gears 11. Shift valve 5. Governor 12. Kickdown cable &throttle cam 6. Shift 13. Throttle / modulator valves 7. Solenoid valve 14. Transmission housing
Fig.
1 Schematic Diagram of Hydraulic Control
I. 1.7 Throttle Valve Mechanism (kick-down)
The throttlevalve or 'kick-down' mechanism comprises a cable connected between throttle body pedal and the throttle
valve cam/ quadrant located on the selector valve shaft; the cam operates the throttle valve housed within the throttle
valve block. The travel of the valve is proportional to throttle positions and alters shift speeds and pressures during
gearshifts to take account of throttle position. The mechanism also provides for immediate selection of a lower
ratio (eg when overtaking) by depressing the accelerator beyond the normal full
-throttle position. 'Kick-down' is oper- ated by movement of the throttle cable into the 'kick-down' position causing full movement of the throttle valve and
directing oil flow to the shift valves.
1.1.8 Starter Inhibit Switch
The starter inhibit switch prevents the starter motor from being operated when the shift lever is not in position 'P' - Park or position 'N'- Neutral. The switch is located in the gear selector housing.
I. I. 9 Gearshift Interlock
A brake pedal /shift lever interlock is incorporated in the gearselector mechanism. Theshift lever may only be moved
from the 'P'- Park position if the ignition key switch is in position '11', and the foot brake pedal is applied. The ignition
key cannot be removed from the ignition switch unless the shift lever is in the 'P' -Park position. Once the ignition key
has been removed, the shift lever is locked in the park position.
The gearshift interlock is operated by an electrical solenoid located adjacent to the selector; an override latch is incorpo
- rated into the mechanism to enable the gearshift interlock to be manually overridden in the event of electrical failure
or when towing.
8 Issue 1 August 1994

ZF Automatic Transmissions Service Manual
1.3 FAULT DIAGNOSIS
The followina tables are intended as a auide to diaanosis of Dossible faults in the ZF 4 HP 22 transmission. When the
fault involvesa leak, it is recommendedthat it is located by the use of a crack detection fluid, eg Met-L-Check, which
is available in spray form and permits the leak to be located after a short test drive.
1.3.1 Initial Checks
Note: Before attempting diagnosis, ensure that the following settings are checked:
Transmission oil level.
. Ensure that the transmission is at normal operating temperature, eg by conducting a road test. If starting from cold,
. Check that the vehicle is on level ground.
. Firmly apply the parking and footbrakes and run the engine at idle speed.
. To ensure that the system is primed, slowly move the selector lever through all the gear positions.
. With the engine still running, engage ‘P‘ Park, withdraw the dipstick and wipe with a lint free cloth.
. Replace the dipstick slowly and withdraw it noting the level.
. Top up as required and recheck the level.
check
for presence of oil on dipstick at idle
in Park before start of road test.
1.3.2 Engine Tune
Selector cable adjustment.
Check gear selection in all selector positions.
If in doubt, select ’N’, disconnect the cable at the gearbox selector lever, check that the gearbox lever is in ’N’ position
. Adjust as necessary, see Vehicle Service Manual.
(third
detent from the rear) and refit the selector cable ball pin to the lever.
Kickdown switch adjustment, see Vehicle Service Manual.
1.3.3 Stall Test
. Ensure the transmission is at normal running temperature.
. Fully apply the parking brake.
. Fully depress the footbrake.
= Select position ‘D‘- Drive.
. Fully depress the accelerator(’kick-down’ detent fully depressed).
. Note the tachometer reading.
Start
the engine.
. Compare the tachometer reading to the specification.
CAUTION: This test must not last more than 5 seconds. Always allow the engine to idle for at least 2 minutes be- tween tests to allow the transmission fluid to cool down. Do not carry out more than three tests in any
half-hour.
1.3.4 Road Test
Fully check all shift speeds and note. Compare the results with the specification in addition to general observations
of transmission behaviour, noises, leaks etc., and consult the following Fault Finding Chart.
CAUTION: When renewing the transmission, ALWAYS flush out the oil cooler and feed and return pipes.
1.3.5 Electrical Checks
If any electrical component fault issuspected, referto the Electrical Diagnostic Manual (EDM) to verify the failure mode
before a repair or replacement is attempted.
Issue 1 August 1994 33

1.3.6 Fault Finding Chart (continued)
Problem Possible Cause
slipping or shaking from start in
'everse gear
Strong jerk, or distant double
erk, when engaging positions
P
-R', or 'N-R' (below 1500RPM
tngine speed)
'B','E or 'D' clutch defective
Damper
'6' defective (will give the
same symptoms when changing
from 2nd to 3rd gears
Action
Service 1 renew transmission.
Service
1 renew valve block
qeverse lamp does not illuminate Starter inhibit switch faulty.
bulbs, fuses and cables
'unctioning correctly) Faulty selector lever.
io drive or severe delay. Renew
switch.
Renew lever.
Slipping or shaking during initial Position
'R' not
selected.
'orward movement
Strong jerk 'N
-D' (below 1500
3PM engine speed) Select
'R'.
Sear change functions
faulty (in c'
Zhange 1st to 2nd 12nd to 1st Governor dirty.
Shift valve 1-2 sticking.
Zhange 1st to
2nd
Renew governor.
Renew valve block.
Zhange 2nd to 3rd
13rd to 2nd
Governor dirty.
Shift valve 3
-4 sticking.
:hange 2nd to 3rd
Zhange 3rd to
4th I 4th to 3rd Renew
governor.
Renew valve block.
Sudden shifts
Jehicle starts in 2nd gear Governor sleeve sticking.
Shift valve 1
-2 sticking.
Governor sleeve sticking.
Shift valves 1
-2 and 2-3 sticking.
Jehicle starts in 3rd gear Renew
governor.
Renew valve block.
Renew governor.
Service
I renew valve block.
Searbox changes 1st to 3rd
Uo shifts Dirty
oil filter.
Oil level incorrect.
'A' clutch defective.
'D' clutch one
-way clutch faulty.
'A' clutch damaged
'A' clutch faulty.
'A' clutch damper faulty.
Id or warm state)
If there is no debris in sump, renew the
oil filter and oil;
if debris is present in
the sump, renew the transmission.
Check oil level.
Service
I renew transmission.
Service
1 renew transmission.
Service
I renew transmision
Service
1 renew transmission.
Service
/ renew valve block.
Brake
'Cl' and 1 or 'C' faulty I Service / renew transmission
Governor dirty.
I Renew governor.
Shift valve 2-3 sticking.
'B' clutch faultv
Renew valve block.
Service
I renew transmission
Dampers sticking
I Service I renew valve block
Shift valve 2
-3 sticking I Service 1 renew valve block
Governor sticking.
Dampers sticking. Change
governor.
Service
I renew valve block
Issue 1 August 1994 35

ZF Automatic Transmissions Service Manual
Problem Possible Cause
1.3.6 Fault Finding Chart (continued)
Action
No changes at light throttle
setting
Change points incorrect at full
throttle setting
No changes at 'kick-down' - 1st
to 2nd 12nd to 1st
No changes at 'kick-down' - 2nd
to 3rd
13rd to 2nd Dirty
governor.
Shift valves sticking.
'Kick
-down' cable setting incorrect
'Kick
-down' cable setting incorrect
'Kick
-down' cable setting incorrect Renew
governor.
Service
1 renew valve block.
Adjust setting
Adjust setting
Adjust setting
Service
1 renew valve block.
Service
1 renew valve block.
Poor changes
Harsh changes at low throttle Throttle
valve ('kickdown') cable
, setting incorrect
I Defective damper.
Modulation pressure too high.
'Kick
-down' cable setting incorrect. I
j Clutch plates damaged.
!
Soft changes at full throttle and
'kick
-down' Defective damper.
'Kick-down' cable setting incorrect.
I
Adjust setting
Service
/ renew valve block.
Service
1 renew valve block.
Adjust setting
,
Service / renew transmission.
Service
/ renew valve block.
Adjust setting.
Adjust setting.
Harsh changes
at full throttle and
'kick
-down' Modulation
pressure too low.
Clutch plates damaged.
Incorrect modulation pressure.
'Kick
-down' cable setting incorrect.
Defective damper.
Manual change 3rd to 2nd faulty
No engine braking
36 Issue 1 August 1994
Locking valve '2' sticking. Service 1 renew valve
block I governor.
Service
/ renew valve block / governor.
Service
1 renew transmission
Governor faulty.
Brake 'C' or 'E' damaged

ZF Automatic Transmissions Service Manual
The torque converter acts in all four forward gears and in reverse. The converter lock-up clutch closes in 4th gear at
a point depending on road speed and accelerator position; engine power is then transmitted
by purely mechanical
means.
A low
-loss oil pump in the front of the transmission housing supplies the converter, the automatic gear shift and the
lubrication circuit; oil is drawn from a sump in the bottom of the gear train housing through a filter. The pump drive
gear is keyed to the converter impeller hub and therefore turns when the engine is running, thereby pressurizing the
oil.
2.1.2 Four-speed Epicyclic Gear Train
The torque converter drives a mechanical epicyclic gear train providing four forward ratios and reverse. Individual ra-
tios are obtained by coupling together the various parts of the gear train by means of solenoid-operated, hydraulically
actuated multi-disc clutches and brakes; built in freewheels permit gear shifts without any interruption of the power
flow.
For information on the operation of the solenoids, clutches, brakes and freewheels, refer to the table below and the
schematic diagrams shown overleaf.
A parking lock pawl is provided at the rear of the gear train, operating on a toothed wheel attached to the output shaft;
the parking lock is operated from the selector (position
'P) by actuator rod.
An electro
-magnetic sensor detects output shaft revolutions by means of a toothed disc attached to the shaft; one rev- olution of the shaft is equal to 36 pulses. The electrical signal from the sensor is passed, via a screened cable, to the
TCM.
R
Park,
Neutral
Solenoid ~
MV2
MVI, MV2
MVI, MV3
MV2
-
MV2
OWC
= one way clutch
Resulting clutch operation
A Clutch drives annulus clockwise
D Clutch OWC holds F carrier against shaft clockwise
E Clutch & OWC drives output shaft clockwise
A Clutch drives annulus clockwise
C1 Clutch holds sungear against anti-clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch
& OWC holds sungear against anti-clockwise
B Clutch drives sungear clockwise
D Clutch holds carrier against clockwise
E Clutch & OWC drives output shaft anti-clockwise
E Clutch & OWC applied (hydraulics)
40
Issue 1 August 1994

ZF Automatic Transmissions Service Manual
2.1.6 Transmission Rotary Switch
This switch is located on a square extension of the transmission selector shaft and is linked to the shift lever via the
selector cable. The switch comprises a selector bar which moves across a series of copper segments located on the
switch quadrant. The copper segments are set out in seven bands, each band providing an electrical output or com
- bination of outputs to the TCM.
The electrical outputs to the TCM are in the form of a three
-digit code which takes up three of the seven bands of the
quadrant; the remaining four bands are used for reverse, ground and start inhibit.
2.1.7 Decoder Module
The decoder module, located on the right hand side of the J-gate assembly, is used to translate the three-digit codes
from the rotary transmission switch into single-line functions to feed the illumination module and to provide the fol-
lowing information:
. Cruise control, ie when cruise control can or cannot be engaged.
. Indication when the vehicle is not in 'P' Park.
. Provide the ECM with a Park/ Neutral signal.
2.1.8 Performance Mode Switch
This switch, located on the shift lever surround, provides two alternative shift patterns:
. 'Normal Mode' -for everyday use,
. 'Sport Mode'- gear changes take place at higher road speeds in order to enhance performance.
Note: Torque converter 'lock-up' occurs in fourth gear in each mode.
2. I. 9 'Kick-down' Mechanism
'Kick-down' is activated by the final travel of the accelerator pedal which contacts a floor-mounted switch located be- hind the pedal. Operation of the switch provides a signal to the TCM that a downward change is required. The switch
is adjustable to ensure that the pedal does not overtravel and stretch the cable.
2.1.10 Reverse Safefy Inhibit
If 'R' Reverse is selected when the vehicle is travelling forwards at more than 5 mile / h, solenoid valve MV2 will be
energised to prevent engagement of reverse gear.
2.1.11 Gearshift hterlock
A brake pedal /gearshift interlock is incorporated in the gear selector mechanism. The gear selector lever may only
be moved from the P - Park position if the ignition key switch is in position II and the foot brake is applied.
The ignition key cannot be removed from the ignition switch unless the shift lever is in
the 'P - Park position. Once
the ignition key has been removed, the shift lever is locked in the park position.
2.1.12 Starter Inhibit Switch
The starter inhibit switch prevents the starter motor from being operated when the shift lever is not in position 'P' - Park or position 'N' - Neutral. The switch is located in the gear selector housing.
issue 1 August 1994 47

ZF Automatic Transmissions Service Manual
0
2.3 FAULT DIAGNOSIS
The following tables are intended as a guide to diagnosis of possible faults in the ZF 4 HP 24 E transmission. When
the fault involves a leak,
it is recommended that it is located by the use of a crack detection fluid, eg. Met-L-Check,
which is available in spray form and permits the leak to be located after a short test drive.
2.3.1 Initial Checks
&@: Before attempting fault diagnosis, ensure that the following settings are checked:
Transmission oil level
. Ensure that the transmission is at normal operating temperature, e.g. by conducting a 20 mile road test. If starting
. Check that the vehicle is on level ground.
. Firmly apply the parking and footbrakes and run the engine at idle speed.
. To ensure that the system is primed, slowly move the selector lever through all the gear positions.
. With the engine still running, engage 'P' Park, withdraw the dipstick and wipe with a lint free cloth.
. Replace the dipstick slowly and withdraw it noting the level.
. Top up as required and recheck the level.
from
cold: check for presence of
oil on dipstick at idle in 'P' Park before setting off.
Note: The oil level can only be accuratelychecked when at normal temperature-approximately 20 miles at moderate
speeds.
2.3.2 Engine Tune
Selector cable adjustment
. Check gear selection in all selector positions.
. If in doubt, select 'N', disconnect the cable at the gearbox selector lever, checkthat the gearbox lever is in 'N' position
. Adjust as necessary at the selector lever inside the vehicle.
(third detent from the rear) and refit the selector cable ball pin to the lever.
2.3.3 Stall Test
. Ensure the transmission is at normal running temperature.
. Fully apply the parking brake.
. Start the engine.
= Fully depress the footbrake.
. Select position 'D'- Drive.
. Fully depress the accelerator('kick-down' switch fully depressed).
. Note the tachometer reading.
. Compare the tachometer reading to the specification.
CAUTION: This test must not last more than 5 seconds. Always allow the engine to idle for at least 2 minutes between
tests to allow the transmission fluid to cool down. Do not carry out more than three tests in any half-hour.
Jaguar Diagnostic Equipment
(JDE) must be interrogated and any faults identified and rectified (see JDS Manual / In- structions). Check mode switch and gear selector positions using JDE.
60 Issue 1 August 1994