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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.
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Problem Possible Cause
2.3.4 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.
Action
CAUTION:
When renewing the transmission, ALWAYS flush out the oil cooler and feed and return pipes.
2.3.5 Electrical Checks
. Check 'Kick-down'.
If any electrical component fault is suspected, refer to Electrical Diagnostic Manual (EDM) to verify the failure mode
before a repair or replacement is attempted.
2.3.6 Fault Finding Chart
Stall speed too low
Stall speed too high and keeps
,ising
hceleration below specification
Top speed below specification
'osition 'P - Park
Nil1 not move out of Park
Ioes not engage Park
Ioes not hold Stator
freewheel faulty allowing stator to
revolve
Engine out of tune
Transmission slip
Engine out of tune
Torque converter freewheel faulty
allowing stator to revolve.
'Kick
-down' switch defective.
Transmission
in 'Limp Home' mode
Engine out of tune
Torque converter freewheel seized
Engine out of tune
Gearshift interlock failure
Check cable adjustment
Parking pawl mechanism sticking
Check cable adjustment
Parking pawl mechanism damaged Renew
torque converter
Check engine tune
Check oil level, check mechanical
failure, renew transmission as
necessary
Check engine tune
Renew torque converter.
Refer to EDM, rectify
I renew
'Kick
-down'switch.
Check.
Check
engine tune
Renew torque converter
Check engine tune
Refer to EDM, rectify
- renew fuse,
check circuits, renew relay and
solenoid.
Check central
'P, check Park switch,
check Brake switch.
Adjust to correct setting
Renew park pawl components:
connecting bar, pawl pin, torsion
spring, pawl, guide piece and guide
sheet.
Adjust to correct setting
Replace park pawl components
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2.3.6 Fault Finding Chart (continued)
Problem
Starter motor does not operate
'osition 'R' - Reverse
3everse gear inoperative
Slipping and juddering
Harsh
engagement'p-R' chan
'N-R' change (below 1500RPF
engine speed)
Reverse lamp does not
illuminate (bulbs, fuses and
cables functioning correctly)
Possible Cause
Rotary switch adjustment.
Rotary switch wiring fault.
Rotary switch faulty.
Position
'P or 'N' not selected.
vIV2 faulty.
rNire to MV2 earthed.
3il filter dirty.
Damper
'6' faulty.
Clutch
'6' faulty (also no 3rd gear).
Clutch 'D' faulty.
Clutch
'E' faulty (also no engine braking
in 2nd and 3rd gears).
Pressure regulator valve 1 binding
Rotary switch wiring fault.
Rotary switch faulty.
Reverse gear inhibit valve activated.
Main pressure control valve seized (also
no forward drive in 'D' Drive).
'B'Clutch, 'D'Clutch or 'E' Clutch faulty.
Pressure regulator valve 1 binding
'F'Clutch drum sealing rings faulty
causing
loss of 'E' Clutch pressure.
Damper
'6' faulty (also no 2nd to 3rd
shift).
Pressure regulator valve 1 binding
Modulation pressure too high.
Rotary switch faulty.
Rotary switch setting incorrect.
Rotary switch faulty.
Rotary switch wiring fault.
Action
4djust switch.
qectify.
3ectify or renew.
Select 'F" or 'N'.
Renew valve block.
Renew harness.
Clean
/ replace filter and flush out
the
oil cooler and pipes.
Renew valve block.
Renew transmission.
Renew transmission.
Renew transmission.
Renew valve block.
Rectify.
Rectify or renew.
Renew valve block.
Renew valve block.
Renew transmission.
Renew valve block.
Renew transmission.
Renew valve block.
Renew valve block.
Check TCM Fault Codes.
Rectify or renew.
Adjust setting.
Renew.
Rectify.
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Problem Possible Cause
2.3.6 Fault Finding Chart (continued)
e Action
Starter will not operate Rotary
switch faulty or incorrect setting. Rectify
or renew.
3rive not transmitted (neutral
:ondition)
Vehicle moves
Slipping and juddering at start Rotary
switch wiring fault. Rectify 'A'Clutch seized Renew
transmission
Checksecurity System
Harsh engagement
'N'-'D'(under 1500RPM engine
speed)
No 1st to 2nd upshift or 2nd to
1st downshift
No upshift 1st to 2nd
No upshift 2nd to 3rd or
downshift 3rd to 2nd
No upshift 2nd to 3rd
3il filter dirty.
Main pressure control valve seized.
Low oil level.
'A'Clutch faulty.
'D'Clutch one-way clutch slips. ~
'A'Clutch faulty
Low oil level.
'A'Clutch faulty.
'A'Clutch damper faulty (5).
Throttle pot. volts high.
Rotary switch faulty
/ out of adjustment.
MVI wire earthed(remains in 2nd gear).
MVI faulty.
Control circuit fault.
Shift valve
1-2 seized.
Pressure reducing valve
1 seized.
Speed sensor or connectors faulty.
Clutches
'Cl' and 'C' faulty
MV2 wire earthed (remains in 2nd gear).
MV2 faulty.
Shift valve 2
-3 seized.
Speed sensor faulty.
'B'Clutch faulty Clean
/ replace
filter.
Renew valve block.
Check oil level.
Renew transmission.
Renew transmission.
Renew transmission.
Check oil level.
Renew transmission.
Renew valve block.
Check throttle pot. volts.
Rectify or renew.
Renew harness.
Renew valve block.
Check TCM Diagnostics
/ rectify.
Renew valve block.
Renew valve block.
Check connections, rectify or
renew.
Renew transmission
Renew harness.
Renew valve block.
Renew valve block.
Rectify or renew.
Renew transmission
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2.3.6 Fault Finding Chart (continued)
Problem
Uo upshift 3rd to 4th or
lownshift 4th to 3rd
Vo upshift 3rd to 4th
lownshift 4th to 3rd too hard
Manual gearshift D to 3rd too
lard
Manual gearshift 3rd to 2nd too
9ard
Vo 1st gear; 2nd gear start only.
No 1st or 2nd gear; 3rd gear
start only
No 2nd gear; transmission shifts
1st to 3rd gear
Light throttle gear change
speeds incorrect
Up to 'kick
-down' detent, gear
change speeds not to
specification
Possible Cause
Shift valve 3-4 seized.
MVl wire earthed.
MV1 faulty.
Speed sensor faulty.
'F'Clutch faulty
3rain orifice 'F' partially blocked.
Damper
'E' faulty.
Damper
'E' faulty.
Drain orifice
'F' partially blocked.
Damper
'Cl' faulty
Speed sensor faulty.
MV1 faulty.
MV1 wire earthed.
Shift valve 1
-2 seized.
'1st Gear Inhibit' circuit operated or
'Performance Mode' switch faulty.
Transmission 'Limp Home' mode.
Speed sensor faulty.
MV1 or MV2 faulty.
Shift valves 1
-2 and 2-3 seized.
Speed sensor faulty.
Shift valve 2
-3 seized.
Shift valves sticking.
Speed sensor faulty.
Throttle pot. volts incorrect.
Transmission Control Module
(TCM).
'Kick-down' switch out of adjustment
3enew valve block.
3enew harness.
Renew valve block.
Rectify or renew.
Renew transmission
Renew valve block.
Renew valve block.
Renew valve block.
Renew valve block.
Renew valve block
Check or renew speed sensor.
Renew valve block.
Renew harness.
Renew valve block.
Operate 'Performance Mode' switch
to correct function or renew switch.
Check Diagnostics
1 JDS.
Renew speed sensor.
Renew valve block.
Renew valve block.
Check or
recheck Diagnostics,
renew speed sensor.
Renew valve block.
Renew valve block.
Check or renew speed sensor.
Check voltage
- JDS.
Check TCM Diagnostics.
Readjust 'kick
-down' switch
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ZF Automatic Transmissions Service Manual
No engine braking
Manual gearchange 3rd to 2nd
inoperative Clutch 'Cl' or
Clutch 'E' faulty
Speed sensor faulty.
MV2 faulty.
a
Renew transmission
Check TCM Diagnostics
1 renew
speed sensor.
Renew valve block.
a
0
Problem
Vo 'kick-down' change
Light throttle speeds only
Light throttle gear change too
hard
1st to
2nd, 2nd to 3rd and 3rd to
4th changes too long
Full load and 'kick
-down'
changes too long
Full load and 'kick
-down'
changes too hard ~
Possible Cause
'Kick-down'
switch out of adjustment 1
full throttle stop adjustment.
'Kick
-down' switch faulty.
'Kick
-down' switch connector or wiring
Fa u Ity.
TCM faulty
Valve block bolt torque incorrect.
Modulation pressure too high.
Damper faulty.
Clutch plates faulty.
Valve block bolt torque incorrect.
Damper faulty.
PRSV faulty.
PRSV wire earthed.
Modulation valve seized.
Pressure regulator valves
1 and 2 seized.
mve block bolt torque incorrect.
Modulation pressure too low.
Clutch plates faulty.
Valve block bolt torque incorrect.
Modulation pressure too low.
Clutch plates faulty.
Action
Adjust as per Engine Set Up
procedure on JDS.
Renew 'kick
-down' switch.
Rectify.
Check TCM
Reset to correct torque.
Renew valve block.
Renew valve block.
Renew gear unit.
Reset to correct torque.
Renew valve block.
Renew valve block.
Renew harness.
Renew valve block.
Renew valve block.
Reset to correct torque.
Renew valve block.
Renew transmission.
Reset to correct torque.
Renew valve block.
Renew transmission.
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3il in bell housing
2.3.6 Fault Finding Chart (continued)
Oil pump seal leaking.
Oil pump 0
-ring leaking.
Pump housing leaking.
Converter seam leaking.
Problem Possible Cause Action
:onverter clutch
-eakage between gearbox and
sump
Leakage between intermediate
date and gearbox
Leakage at harness plug
:onnector
Leakage at drive flange
:Iutch engagement speed
ncorrect
Loose fastening screws.
Sump gasket faulty.
Bell housing to gearbox screws loose
Connector 'O'ring faulty
Rear oil seal faulty
ingagement
too hard
Jo clutch engagement
Ionverter clutch engaging at
dle (engine will not idle in
'D')
Control circuit fault.
Speed sensor faulty.
Valve body problem.
Converter unit faulty
Control circuit fault
MV3 faulty.
Converter clutch valve seized.
Converter faulty. Pressure reducing valve
1 seized.
Incorrect oil level.
Oil filter not sealing.
Control circuit fault.
MV3 faulty.
MV3 wire earthed.
Converter clutch valve
sticking.
Check TCM Diagnostics / rectify
fault.
Check TCM Diagnostics
1 renew
speed sensor.
Renew valve body
Renew converter unit
Check TCM Diagnostics
1 rectify
fault.
Renew valve block.
Renew valve block.
Renew converter.
Renew valve block.
Check oil level.
Check 0
-ring etc.
Check TCM Diagnostics
/ rectify
fault.
Renew valve block.
Renew harness.
Renew valve block.
Renew oil pump seal.
Renew 0
-ring.
Renew oil pump.
Renew converter.
Torque tighten.
Renew gasket.
Torque tighten
Renew
'0' ring
Renew oil seal
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2.3.6 Fault Finding Chart (continued)
a
0
0
a
Problem
Leakage at breather
Leakage from oil cooler circuit
Leakage at intermediate plate
Leakage between gearbox and
extension housing
General
Noise and associated
interruption of power
Loud noise with no drive
forward or reverse
Groaning or buzzing noise (can
sound like mechanical damage)
in all selector positions,
especially when cold.
Sucking noise from pump.
Loud noise on converter clutch
engagement
Engine vibrations when
converter clutch engaged
Possible Cause
Oil level too high.
Incorrect oil specification.
Breather cover missing.
Breather cover
'0' ring faulty.
Breather cover loose.
Pipe lock nuts loose.
Pipe line faulty.
Oil cooler leaking.
Intermediate plate plug leaking
Fastening screws loose. Gasket
faultv.
Oil filter dirty
Drive plate to converter connection
damaged.
Pump drive damaged.
Oil level too low.
Valve block leaking.
Torsion damper defective
Change point too low
Action
Rectify.
Change
oil and flush system.
Replace breather cover.
Renew
'0' ring.
Renew lockwasher.
Torque tighten.
Renew relevant pipes.
Renew oil cooler.
Torque tighten plug.
Renew sealing washer.
Torque tighten
Renew gasket.
Clean
/ replace filter. If clutch debris
found, renew transmission, flush
cooling system
Renew drive plate and converter as
necessary.
Renew transmission.
Rectify.
Renew valve block.
Renew converter
Check TCM
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