2000 MITSUBISHI MONTERO ECU

AUTOMATIC TRANSMISSION -Troubleshooting 23-48
INSPECTION PROCEDURES CLASSIFIED BY TROUBLE SYMPTOM
Inspection procedure 1
Communication with the MUT-II
is not possible.
Probable cause
If communication with the MUT-
IIis not possible, the cause is probably a
malfunction of the diagnosis line or the A/T-ECU is not functioning.DMalfunction of diagnosis line
DMalfunction of harness or connector
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
Is communication with other systems possible
using the MUT-
II?NOCheck the MUT-
IIdiagnosis line, and repair if
necessary.
YES
Measure at engine-A/T-ECU connector D-120,
D-121 <6G7>, or at A/T-ECU connectors D-107
and D-109 <4M4>.
DDisconnect the connector and measure at the
harness side.
DIgnition switch: ON
<6G7> Voltage between terminals 41, 47 and
earth
<4M4> Voltage between terminals 11, 24 and
earth
OKSystem voltage
<6G7> Continuity between terminals 76, 97,
88 and earth
<4M4> Continuity between terminals 13, 25,
26, 12, 72 and earth
OKContinuityOKCheck the following connectors:<6G7> D-120,
D-121, <4M4> D-107,D-109NG
Repair
OK
Check the trouble symptoms.
NG
Replace the engine-A/T-ECU or A/T-ECU.
NG
NG
Repair
OK
Check the trouble symptoms.NGDCheck the harness between the
engine-A/T-ECU and the ignition switch, and
repair if necessary. <6G7>
DCheck the harness between the A/T-ECU and
the ignition switch, and repair if necessary.
<4M4>
DCheck the harness between the
engine-A/T-ECU and earth, and repair if
necessary. <6G7>
DCheck the harness between the A/T-ECU and
earth, and repair if necessary.<4M4>
Check the following connectors:<6G7> A-04,
B-25X, D-128, D-120, D-121, D-14,<4M4> D-208,
D-213, D-32, E-13, D-107, D-109, D-14


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AUTOMATIC TRANSMISSION -Troubleshooting 23-49
Inspection procedure 2
Starting not possible
Probable cause
If the enginewill not start when the selector lever is at the P or N position, the
cause is probably a malfunction of the inhibitor switch system, the transmission
control cable assembly, theenginesystem, the torque converter or the oil pump.DMalfunction of inhibitor switch system
DMalfunction of transmission control cable assembly
DMalfunction of enginesystem
DMalfunction of torque converter
DMalfunction of oil pump
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
NG
Inspection Procedure 16: Inhibitor switch system check (Refer
to P.23-58.)NG
Repair or replace
OK
Torque converter check
DCheck for incorrect installation (inserted at an angle, etc.)
or damagedsplines.NGIf repair is possible, repair the damaged part.
If repair is not possible because the splines aredamaged,
replace the torque converter assembly.
OK
Replace the oil pumpassembly.
L
(The oilpump cannot be disassembled.)
Engine system check
DControl system, ignition system, fuel system, vehicle bodyNG
Repair
OK
Transmission control cable assembly checkNG
Repair OK
Check the trouble symptoms.Replace the engine-A/T-ECU or A/T-ECU.
Inspection procedure 3
Does not move forward
Probable cause
If the vehicle does not move forward when theengine is idling and theselector
lever is moved from N to D, 3, 2 or L, or if it is shifted to 1st or 2nd in Sports
mode, the cause is probably a problem with line pressure, or a malfunction of
the UD clutch or valve body.DAbnormal line pressure
DMalfunction of UD solenoid valve
DMalfunction of UD clutch system
DMalfunction of valve body
DMalfunction of engine-A/T-ECU <6G7>
DMalfunction of A/T-ECU<4M4>
LRefer to the Transmission Workshop Manual.
MUT-
IIActuator Test
DNo.2 UD solenoid valve
OK:Sound of operation can be heardNGReplace the solenoid valve.
L
OK
Fluid pressure test (Refer to P.23-106.)
DMeasure the fluid pressure at each element in 1st in
Sportsmode
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
UD clutch system check
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.
UD clutch check
L
DCheck for a problem such as burnt facing, poor piston
sealing or interference with the retainer.OKCheck the trouble symptoms. NG
Replace the engine-A/T-ECU or A/T-ECU.NG


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AUTOMATIC TRANSMISSION -Troubleshooting 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 AUTOMATIC TRANSMISSION -Troubleshooting 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 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 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 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 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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