MITSUBISHI MONTERO 2000 Service Repair Manual

AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-50
Inspection procedure 4
Does not reverse
Probable cause
If the vehicle does not reverse when theengine is idling and theselector lever
is moved from N to R, the cause is probably a problem with reverse clutch
pressure or LR brake pressure, or a malfunction of the reverse clutch, LD clutch
or valve body.DAbnormal reverse clutch pressure
DAbnormal LR brake pressure
DMalfunction of LR solenoid valve
DMalfunction of reverse clutch
DMalfunction of LR brake
DMalfunction of valve body
DReplacement of engine-A/T-ECU <6G7>
DReplacement of A/T-ECU.<4M4>
LRefer to the Transmission Workshop Manual.
NGReplace the solenoid valve.
L
OK
NG
OK
NG
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
OK
Reverse clutch system and LR brake system check
L
DRemove the transmission assembly, the valve body cover
and the valve body.
DBlow air through the reverse clutch oilhole or LRbrake
air hole in the transmissioncase, and check that the
piston operates to maintain pressure.OK
Check the reverse clutch and LR brake.
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.NGCheck the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
MUT-
IIActuator Test
DNo. 1 LR solenoid valve
OK:Sound of operation can be heard
Fluid pressure test (Refer to P.23-106.)
DMeasure the reverse clutch fluid pressure in R range.
Standard value:Refer to P.23-106.
Fluid pressure test (Refer to P.23-106.)
DMeasure the LR brake fluid pressure in R range.
Standard value:Refer to P.23-106.


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-51
Inspection procedure 5
Does not move (forward or reverse)
Probable cause
If the vehicle does not move forward or reverse when the selector lever is
moved to any position while the engine is idling, thecause is probably a
problem with line pressure or a malfunction of the oil pumps and valve bodies in
the power train.DAbnormal line pressure
DMalfunction of power train components
DMalfunction of oil pump
DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
Fluid pressure test (Refer to P.23-106.)
DMeasure the fluid pressure at each element in 1st, 2nd
and reverse.
Standard value:Refer to P.23-106.OKCheck the power train components
L
DDisassemble the transmission and check the condition of
components such as the planetary carrier, output shaft and
differential.
NG
Replace the oil pumpassembly.
L
(The oilpump cannot be disassembled.)
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.NG
NG
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.
Inspection procedure 6
Engine stalls during shifting
Probable cause
If the enginestalls when the selector lever is moved from N to D or R while the
engine is idling, thecause is probably a malfunction of theenginesystem, DCC
solenoid valve, valve body, or torque converter (damper clutch).DMalfunction of enginesystem
DMalfunction of DCC solenoid valve
DMalfunction of valve body
DMalfunction of torque converter (malfunction of
damper clutch)
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
Engine system check
DControl system, ignition system, fuel system, vehicle bodyNG
Repair or replace
OK
Replace the DCC solenoid valve.
L
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.NGReplace the torque converter assembly.
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-52
Inspection procedure 7
N-to-D shocks, large time lag
Probable cause
If abnormalshocks or atime lag of 2 seconds or more occurs when the
selector lever is moved from N to D while theengine is idling, thecause is
probably abnormal UD clutch pressure, or a malfunction of the UD clutch, valve
body or APS.DAbnormal UD clutch pressure
DMalfunction of UD solenoid valve
DMalfunction of UD clutch system
DMalfunction of valve body
DMalfunction of APS
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
NO
MUT-
IIActuator Test
DNo.2 UD solenoid valve
OK:Sound of operation can be heardNGReplace the solenoid valve.
L
OK
When starting off
Shocks are sometimes generated.
NG
UD clutch check
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.
NG
Code No. 11, 12, 14 APS system check (Refer to P.23-13, 14
and 15.)
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
OK
During shifting
Fluid pressure test (Refer to P.23-106.)
DMeasure the UD clutch fluid pressure when shifting from N
to D.
Standard value:Refer to P.23-106.MUT-
IIData List
DNo.11 APS
OK:Increases in proportion to the acceleratorpedal open-
ing angle.
YES
OK OK
UD clutch system check
L
DRemove the transmission assembly, the valve body cover
and the valve body.
DBlow air through the UD clutch oilhole in the transmission
case, and check that the piston operates to maintain
pressure.NG
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
When areshocksgenerated?


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-53
Inspection procedure 8
N to R shocks, large time lag
Probable cause
If abnormalshocks or atime lag of 2 seconds or more occurs when the
selector lever is moved from N to R while theengine is idling, thecause is
probably abnormal reverse clutch pressure or LD brake pressure, or a
malfunction of the reverse clutch, LR brake, valve body or APS.DAbnormal reverse clutch pressure
DAbnormal LR brake pressure
DMalfunction of LR solenoid valve
DMalfunction of reverse clutch
DMalfunction of LR brake
DMalfunction of valve body
DMalfunction of APS
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
NGReplace the solenoid valve.
L
NG
Check the reverse clutch and LR brake.
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.
OK
Reverse clutch system and LR brake system check
L
DRemove the transmission assembly, the valve body cover
and the valve body.
DBlow air through the reverse clutch oilhole or LRbrake
air hole in the transmissioncase, and check that the
piston operates to maintain pressure.
NG
Code No. 11, 12, 14 APS system check (Refer to P.23-13, 14
and 15.)
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
OK
NG
OK
Fluid pressure test (Refer to P.23-106.)
DMeasure the LR brake fluid pressure in R range.
Standard value:Refer to P.23-106.NO
NG
During shifting
Fluid pressure test (Refer to P.23-106.)
DMeasure the reverse clutch fluid pressure in R range.
Standard value:Refer to P.23-106.MUT-
IIData List
DNo.11 APS
OK:Increases in proportion to the acceleratorpedal open-
ing angle.
YES
OK
OK
When areshocksgenerated?When starting offShocks are sometimes generated.
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
MUT-
IIActuator Test
DNo. 1 LR solenoid valve
OK:Sound of operation can be heard


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-54
Inspection procedure 9
N-to-D and N-to-R shocks, large time lag
Probable cause
If abnormalshocks or atime lag of 2 seconds or more occurs when the
selector lever is moved from N to both D and R while theengine is idling, the
cause is probably abnormal line pressure, or a malfunction of the oilpump or
valve body.DAbnormal line pressure
DMalfunction of oil pump
DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
OK
When areshocksgenerated?
During shifting
Replace the oil pumpassembly.
L
(The oilpump cannot be disassembled.)When starting off
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.NG
Fluid pressure test (Refer to P.23-106.)
DMeasure the fluid pressure at each element in 1st, 2nd
and reverse.
Standard value:Refer to P.23-106.NGAdjust the line pressure. (Refer to P.23-111.)
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
Inspection procedure 10
Shocks, engine racing
Probable cause
If shocks occur whendriving due to upshifting or downshifting, or the
transmission speed becomes higher than theengine speed, thecause is
probably abnormal line pressure or a malfunction of a solenoid valve, oil pump,
valve body or of a brake or clutch.DAbnormal line pressure
DMalfunction of solenoid valve
DMalfunction of oil pump
DMalfunction of valve body
DMalfunction of brake or clutch
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
MUT-
IIActuator Test
DNo.1 LR solenoid valve
DNo.2 UD solenoid valve
DNo.3 2ND solenoid valve
DNo.4 OD solenoid valve
DNo.5 RED solenoid valve
OK:Sound of operation can be heardNGReplace the solenoid valve.
L
OK
Adjust the line pressure. (Refer to P.23-111.)NGReplace the oil pumpassembly.
L
(The oilpump cannot be disassembled.)
OK
Brake and clutch check
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.NG
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
Replace the engine-A/T-ECU or A/T-ECU.
Check the trouble symptoms.
NG


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-55
Inspection procedure 11
All points (incorrect shift points)
Probable cause
If all shift points are incorrect during driving, the cause is probably a malfunction
of the output speed sensor, APS or solenoid valve.DMalfunction of output shaft speed sensor
DMalfunction of APS
DMalfunction of solenoid valve
DAbnormal line pressure
DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
NGCode No. 23 Output shaft speed sensor system (Refer to
P.23-22.)
OK
NG
Code No. 11, 12, 14 APS system check (Refer to P.23-13, 14
and 15.)
OK
MUT-
IIData List
DNo. 31 RED solenoid valve duty ratio
DNo. 32 UD solenoid valve duty ratio
DNo. 33 2ND solenoid valve duty ratio
DNo. 34 OD solenoid valve duty ratio
DNo. 35 RED solenoid valve duty ratio
OK:
No.31 No.32 No.33 No.34 No.35
Driving at aconstant speed in 1st
0% 0% 100% 100% 0%
Driving at a constant speed in 2nd
100% 0% 0% 100% 0%
Driving at a constant speed in 3rd
100% 0% 100% 0% 0%
Driving at a constant speed in 4th
0% 0% 100% 0% 100%
Driving at a constant speed in 5th
0% 100% 0% 0% 100%NGReplace the solenoid valve.
L
NG
Check the trouble symptoms.
OK
Adjust the line pressure. (Refer to P.23-111.)
NG
Disassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
Replace the engine-A/T-ECU or A/T-ECU.
MUT-
IIData List
DNo. 23 Output shaft speed sensor system
OK:Increases in proportion to vehicle speed.
MUT-
IIData List
DNo.11 APS
OK:Increases in proportion to the acceleratorpedal open-
ing angle.


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-56
Inspection procedure 12
Some points (incorrect shift points)
Probable cause
If some of the shift points are incorrect while driving, the cause is probably a
malfunction of the valve body, or it is a characteristic of control and is not a
malfunction.DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
INVECS-
IIcancel command
DCancels INVECS-
IIusing MUT-
II.
YES
Problem is a characteristic of control
and is not a malfunction. YES
Is standard shifting normal?NODoes the problem occur when the
ATF temperature is less than 35
°C
or higher than 120
°C?NODisassemble, clean and re-assemble
the valve body.
L
DMake sure that the mounting
bolts are not loose and that the
O-ring and valve body are not
damaged or positionedincorrectly.
DIf the extent of thedamagelooks
too bad for repairs to be carried
out, replace the valve body
assembly.
Check the trouble symptoms.
Replace the engine-A/T-ECU or
A/T-ECU.NG
Inspection procedure 13
No diagnosis code (no shifting)
Probable cause
No shifting during driving
However, if a diagnosis code is not output, the cause is probably malfunction of
the inhibitor switch system, the shift switch assembly, theengine A/T-ECU or
the A/T-ECU.DMalfunction of Inhibitor switch
DMalfunction of shift switch assembly system
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
Does the transmission stay at 3rd in
D range?NOMUT-
IIData List
DNo. 61 Inhibitor switch
OK:The ECU input signal and
the selector lever position
should correspond.NGInspection Procedure 16: Inhibitor
switch system check (Refer to
P.23-58.)
YES
OK
NG
Inspection Procedure 17: Shift switch
assembly system check (Refer to
P.23-58.)
NO
Power supply circuit check
DCheck for anopencircuit in the
harness, a poor connector
connection or a blown fuse wire.
DIf there is a blown fuse, check
for whatever caused the blown
fuse and replace the problem
part.
YES
Replace the engine-A/T-ECU or
A/T-ECU.
MUT-
IIData List
DNo.67 Select switch
DNo.68 Shift switch (UP)
DNo.69 Shift switch (DOWN)
OK:The ECU input signal and
the selector lever position
should correspond.
Check the trouble symptoms.OK
NG
YES
Is powerbeing supplied to the
A/T-ECU or to the
engine-A/T-ECU? NO
Is the backup power supplybeing
supplied to the A/T-ECU or to the
engine-A/T-ECU?


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-57
Inspection procedure 14
Poor acceleration
Probable cause
If the vehicle does not accelerate after downshifting, the cause is probably a
malfunction of the enginesystem or of a brake or clutch.DMalfunction of enginesystem
DMalfunction of brake or clutch
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
Engine system check
DControl system, ignition system, fuel system, vehicle bodyNG
Repair or replace
OK
Brake and clutch check
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
Inspection procedure 15
Vibration
Probable cause
If vibration occurs when accelerating or decelerating while driving at a constant
speed or driving in top range, the cause is probably abnormal damper clutch
pressure, or a malfunction of theenginesystem, DCC solenoid valve, torque
converter or valve body.DAbnormal damper clutch pressure
DMalfunction of enginesystem
DMalfunction of DCC solenoid valve
DMalfunction of torque converter
DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
NGReplace the DCC solenoid valve.
L
OK
Does the problem still occur when theengine coolant
temperature sensor is disconnected?YESEngine system check
DControl system, ignition system, fuel system, vehicle body
NO
Fluid pressure test (Refer to P.23-106.)
DMeasure the damper clutch fluid pressure.
Standard value:Refer to P.23-106.NGDisassemble, clean and re-assemble the valve body.
L
DMake sure that the mounting bolts are not loose and that
the O-ring and valve body are notdamaged or positioned
incorrectly.
DIf the extent of thedamagelooks too bad for repairs to be
carried out, replace the valve body assembly.
OK
Replace the torque converter assembly.Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.OK
MUT-
IIActuator Test
DNo. 6 DCC solenoid valve
OK:Sound of operation can be heard


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-58
Inspection procedure 16
Inhibitor switch system
Probable cause
The cause is probably a malfunction of the inhibitor switch circuit or the ignition
switch circuit.DMalfunction of Inhibitor switch
DMalfunction of ignition switch
DMalfunction of harness or connector
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
Inhibitor switch check (Refer to P.23-98.)NG
OK
Inhibitor switch connector C-05 voltage check
DDisconnect the connector and measure at the
harness side.
DVoltage between terminal 7 and earth
(Ignition switch: ON)
OK:System voltage
OKCheck the following connectors:D-208, D-213,
D-32, E-115, C-05NG
Repair
OK
Check the harness between the inhibitor switch
and the ignition switch.
OK
Check the trouble symptoms.
NGNG
Repair
Check the trouble symptoms.Replace
NG
Repair
Ignition switch check
NG
Repair
DCheck the harness between the inhibitor
switch and the engine-A/T-ECU. <6G7>
DCheck the harness between the inhibitor
switch and the A/T-ECU.<4M4>
OK
Replace the engine-A/T-ECU or A/T-ECU. NGNG
OK
Check the following connectors:<6G7> C-05,
E-113, D-128, D-122, <4M4>C-05, E-115, D-128,
B-109
Inspection procedure 17
Shift switch assembly system
Probable cause
The cause is probably a malfunction of the inhibitor switch circuit, shift switch
assembly circuit, or of the engine-A/T-ECU or A/T-ECU.DMalfunction of inhibitor switch
DMalfunction of select switch
DMalfunction of shift switch (UP)
DMalfunction of shift switch (DOWN)
DMalfunction of harness or connector
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
Inhibitor switch check (Refer to P.23-98.)NGInhibitor switch check
DInspection Procedure 16: Inhibitor switch system check
(Refer to P.23-58.)
OK
Shift switch assembly check (Refer to P.23-117.)NG
Replace
OK
DCheck the harness between the shift switch assembly and
the engine-A/T-ECU. <6G7>
DCheck the harness between the shift switch assembly and
the A/T-ECU.<4M4>NG
Repair
OK
Check the trouble symptoms.NGReplace the engine-A/T-ECU or A/T-ECU.
OK
Check the following connectors:<6G7> E-117, E-113,
D-122, <4M4> E-117, E-113,D-109NG
Repair


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AUTOMATIC TRANSMISSION -Troubleshooting <A/T>23-59
Inspection procedure 18
Dual pressure switch system
Probable cause
The cause is probably a malfunction of thedualpressure switch circuit, or of the
engine-A/T-ECU or A/T-ECU.DMalfunction of dualpressure switch
DMalfunction of harness or connector
DMalfunction of A/C system
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
Dual pressure switch check
(Refer to GROUP 55 – On-Vehicle Service.)NG
Measure at engine-A/T-ECU connector D-121
<6G7> or at A/T-ECU connector D-107 <4M4>.
DDisconnect the connector and measure at the
harness side.
DIgnition switch: ON
DA/C switch: ON
D<6G7> Voltage between terminal 83 and earth
<4M4> Voltage between terminal 10 and
earth
OK:System voltage
OKCheck the following connectors:<6G7> D-121,
A-04,<4M4> D-107,A-04NG
Repair OK
Check the trouble symptoms.Replace
A/C system check (Refer to GROUP 55 -
Troubleshooting.)NG
Replace the engine-A/T-ECU or A/T-ECU. NG
Inspection procedure 19
Vehicle speed sensor system
Probable cause
The cause is probably a malfunction of the vehicle speed sensor circuit, or of
the A/T-ECU or the engine-A/T-ECU.DMalfunction of vehicle speed sensor
DMalfunction of connector
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
MUT-
IIData List
DNo.29 Vehicle speed sensor
OK:Refer to P.23-61 (Data List Chart).NO
Speedometer check
(Refer to GROUP 54A - Combination Meter.)
OK
OKNG NG
YES
Is the speedometer correct?
OK
Transient malfunction (Refer to GROUP 00 - Points to Note
for Transient Malfunctions.)
Check the trouble symptoms.
Replace the engine-A/T-ECU or A/T-ECU.NG
Check the following connectors:<6G7> C-09, E-113, E-13,
D-121<4M4>C-09, E-113, E-13, D-109
DCheck the harness between the engine-A/T-ECU and the
vehicle speed sensor. <6G7>
DCheck the harness between the A/T-ECU and the vehicle
speed sensor.<4M4>Repair
NG
Repair


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