2000 MITSUBISHI MONTERO Service Repair Manual

MITSUBISHI SC-Troubleshooting13E-12
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble SymptomInspection
procedure
No.Reference
page
Communication with MUT-II is not possible.113E-12
Communication with MUT-II and the SC-ECU is not possible.213E-13
The SC warning lamp does not illuminate when the ignition key is turned to ON (engine
stopped).313E-14
The SC warning lamp remains illuminated after the engine has started.413E-14
INSPECTION PROCEDURES FOR TROUBLE SYMPTOMS
Inspection procedure 1
Communication with MUT-
IIis not possible.
Probable cause
The cause is probably a malfunction of the diagnosis connector power supply
circuit or earth circuit.DMalfunction of diagnosis connector
DMalfunction of harness or connector
NGCheck the following connectors:
D-27, D-211, D-210, D-23
NG
Repair
OK
Check the trouble symptoms.
NG
Check the harness wire between battery and diagnosis
connector, and repair if necessary.
OK
NG
NG
Repair
OK
Check the trouble symptoms.
NG
Check the harness wire between diagnosis connector and
earth, and repair if necessary.
OK
NG
Replace the MUT-
II.
Measure at diagnosis connecter D-23.
DVoltage between 16 and body earth
OK:
System voltage
Check the following connector:
D-23Measure at diagnosis connecter D-23.
DContinuity between terminals 4, 5 and body earth
OK:
Continuity
Check the trouble symptoms.


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MITSUBISHI SC-Troubleshooting13E-13
Inspection procedure 2
Communication with MUT-
IIand the SC-ECU is not
possible.
Probable cause
The cause is probably an open circuit in the SC-ECU power supply circuit or an
open circuit in the diagnosis output circuit.DMalfunction of harness or connector
DMalfunction of the SC-ECU
NG
Repair
OK
Check the trouble symptoms.
NG
Check the harness wire between SC-ECU and diagnosis
connector, and repair if necessary.
OK
Measure at SC-ECU connector E-121 and diagnosis connector
D-23.
DDisconnect the connectors and measure at the harness
side.
DContinuity between the following terminals:
Between terminals 1 (SC-ECU side) and 1 (diagnosis
connector side)
Between terminals 14 (SC-ECU side) and 7 (diagnosis
connector side)
Between terminals 23 (SC-ECU side) and 14 (diagnosis
connector side)
OK:
ContinuityNGCheck the following connectors:
E-121, E-122, D-128, E-13,
D-33, D-222, D-23
OK
NG
Repair
OK
Check the trouble symptoms.
NG
OKNG
Repair
OK
(1)NGCheck the following connectors:
B-25X, D-128, E-122,
E-121
NG
Check the harness wire between the engine control relay and
the SC-ECU, and repair if necessary. (2)NG
OK
Check the trouble symptoms.
NG
Replace
NG
Check the harness wire between the battery and the SC-ECU,
and repair if necessary.
Check the following connectors:
D-27, D-223 ,
D-31 , E-13, E-122, E-120
Measure at SC-ECU connectors E-120, E-121.
DDisconnect the connector and measure at the harness
side.
(1) Voltage between terminal 25 and body earth
(Ignition switch: ON)
OK:
System voltage
(2) Voltage between terminal 39 and body earth
OK:
System voltage
NG (1)NG
Check the harness wire between the SC-ECU and the body
earth, and repair if necessary.
Repair
NG
Replace the SC-ECU.
Check the trouble symptoms.
Check the following connectors:
E-120, E-122
NG
(2), (3)NG
Check the harness wire between the SC-ECU and the body
earth, and repair if necessary.
OK
NG
Repair
NGCheck the trouble symptoms.
Check the following connector:
E-121, E-122
OK
Check the trouble symptoms.
Measure at SC-ECU connector E-120, E-121.
DDisconnect the connector and measure at the harness
side.
(1) Continuity between 31 and body earth
OK:
Continuity
(2) Continuity between 13 and body earth
OK:
Continuity
(3) Continuity between 26 and body earth
OK:
Continuity
Check the trouble symptoms.
Check the fusible link No.2 and dedicated fuse No.7


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MITSUBISHI SC-Troubleshooting13E-14
Inspection procedure 3
The SC warning lamp does not illuminate when the
ignition key is turned to ON (engine stopped).
Probable cause
When the ignition switch is turned on, the SC-ECU starts to communicate with
the engine-ECU or engine-A/T-ECU. Then the SC-ECU will illuminate the SC
warning lamp if the engine speed is 350 rpm or less. If the SC warning lamp
does not illuminate, the case is probably an open circuit in the SC warning lamp
power supply circuit, a blow lamp bulb or an open circuit between the SC
warning lamp and the SC-ECU.DBlown fuse
DBlown SC warning lamp bulb
DMalfunction of harness or connector
DMalfunction of combination meter
DMalfunction of the SC-ECU
NG
Replace the combination meter.
NG
Repair
OK
NG
Check for a blown bulb.Replace the SC
warning lamp bulb.
OK
NG
Repair
OK
Check the trouble symptoms.
Multi - purpose fuse No. 6 checkNGRefer to Basic Manual GROUP 00 – Inspection service Points
for Blown Fuse.
NG
Check the harness wire.
DBetween the ignition switch and the combination meter
DBetween the combination meter and the SC-ECU
OK
OK
Replace the SC-ECU
Check the following connector:
E-107
NG
RepairCheck the trouble symptoms.OK
NG
Check the following connectors:
D-208, D-210 ,
D-213 , D-01, E-10, E-122, E-120
Measure at the SC-ECU connector E-120.
DDisconnect the connector and measure at the harness
side.
DIgnition switch: ON
DWarning lamp condition when terminal 45 is shorted to
body earth
OK:
Illuminates
Inspection procedure 4
The SC warning lamp remains illuminated after the
engine has started.
Probable cause
The cause is probably a short-circuit in the SC warning lamp illumination circuit.DMalfunction of combination meter
DMalfunction of harness (short-circuit)
DMalfunction of the SC-ECU
NOTE
This trouble symptom is limited to cases where communication with the MUT-II is possible(SC-ECU power
supply is normal) and the diagnosis code is a normal diagnosis code.
When the SC-ECU connector E-120 are disconnected and the
ignition switch is turned to the ON position, does the SC
warning lamp remain illuminated?YES
NO
Replace the SC-ECU.Replace the combination meter.
NG
Repair
OK
Check the harness wire between the combination meter and
the SC-ECU


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MITSUBISHI SC-Troubleshooting13E-15
DATA LIST REFERENCE TABLE
The following ECU input data items can be read using the MUT-
II.
Item
No.Check itemInspection conditionsNormal condition
10Vehicle speedWhen vehicle is being drivenSpeedometer display and
MUT-IIdisplay are identical.
11AcceleratorIgnition switch:Release the accelerator pedal.0.9 - 1.1 V
pedal position
sensorONDepress the accelerator pedal gradually.Increases in response to
pedal depression stroke.
Depress the accelerator pedal fully4.0 V or more
18Power supply
voltageIgnition switch: ONSystem voltage
19Accelerator
pedal positionIgnition switch:
ONRelease the accelerator pedalON
pedal position
switch (Idle
switch)ON
Depress the accelerator pedal slightly.OFF
20Ignition switchIgnition switch: ONON
Ignition switch: OFFOFF
22Front-right
wheel speedWhen vehicle is being drivenSpeedometer display and
MUT-IIdisplay are identical.
28Engine typeVehicles with the 6G74 engine6G74
Vehicles with the 4M41 engine4M41
30Trace controlSC system control is activeON
SC system control is not activeOFF
31Engine specifi-Vehicles with the 6G74 engineDOHC
cation 1Vehicles with the 4M41 engine-
32Engine specifi-Vehicles with the 6G74 engineN/A
cation 2Vehicles with the 4M41 engine-
33Engine specifi-Vehicles with the 6G74 engineMIVEC/ETV
cation 3Vehicles with the 4M41 engine-
35Destination-EC
40Engine speedDepress the accelerator pedal gradually.Tachometer display and
MUT-IIdisplay are identical.
51Inhibitor switchIgnition switch:Selector lever position: PP
ONSelector lever position: RREngine:
stopped
Selector lever position: NN
Selector lever position: DD
52Shift positionSelector lever
position: sportsDriving at a constant speed of 10 km/h in
1st1st
modeDriving at a constant speed of 30 km/h in
2nd2nd
Driving at a constant speed of 50 km/h in
3rd3rd
Driving at a constant speed of 50 km/h in
4th4th
Driving at a constant speed of 70 km/h in
5th5th


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6
3 G
se nso r 2
.3 5 -2.6 5 V W
hen ve hic le is bein g driv e n 1
.0 -4.0 V C
heck it e m D
riv e Conte nts 0
5 O
pera tio n Te st of MIT -
S U BIS H IS C T
ra nsm it s th e sig nal, w hic h re quests no to rq ue and wid e open th ro ttle ,to
t h e engin e-E C U or engin e-A /T -E C U fo r th re e se co nds. H
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C
heck it e m I
n sp ectio n co ndit io ns N
orm alc o ndit io n 1 D
ia gnosis se le ct in put W
hen th e M UT-II is co nnecte d 1
V or le ss W
hen th e M UT-II is notco nnecte d A
ppro x. 5 V 1
4 M
UT-II S
eria lc o m munic a tio n
w it h th e M UT-II 1
V or le ss 1
5,1 6 A
/T -E C U <4M 41-A /T > I
g nit io n sw it c h : O N S
eria lc o m munic a tio n
w it h th e SC -E C U I
g nit io n sw it c h : O FF 0
V 1
7,1 8 E
ngin e-E C U or
E ngin e-A /T -E C U <6G 74-A /T > I
g nit io n sw it c h : O N S
eria lc o m munic a tio n
w it h th e SC -E C U I
g nit io n sw it c h : O FF 0
V 1
9 G
se nso r in put I
g nit io n sw it c h : O N
V ehic le horiz o nta lp osit io n 2
.4 -2.6 V 2
1 A
BS-E C U [w heel sp eed se nso r
( F R )] in put I
g nit io n sw it c h : O N
M ove th e ve hic le slo w ly fo rw ard 0
V and 5 V alt e rn ate s 2
3 V
ehic le sp eed se nso r in put I
g nit io n sw it c h : O N
M ove th e ve hic le slo w ly fo rw ard 0
V and 8 -12 V
a lt e rn ate s 2
5 S
C -E C U pow er su pply I
g nit io n sw it c h : O N S
yste m vo lt a ge I
g nit io n sw it c h : O FF 0
V 3
9 S
C -E C U backu p pow er su pply A
ta ll tim e S
yste m vo lt a ge 4
5 S
C warn in g la m poutp ut I
g nit io n W
hen la m pis sw it c h ed off S
yste m vo lt a ge s
w it c h : O N W
hen la m pis illu m in ate d 2
V or le ss A
cce le ra to r
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MITSUBISHI SC-Troubleshooting/On-vehicle Service13E-18
Terminal No.Signal nameNormal condition
Between terminal 13 and body earthEarthContinuity
Between terminal 26 and body earthEarth
Between terminal 31 and body earthEarth
ON-VEHICLE SERVICE
OPERATION TEST OF MITSUBISHI SC
1. Connect the MUT-
IIto the 16-pin diagnosis connector.
Caution
Turn the ignition switch to the LOCK (OFF) position
when connecting and disconnecting the MUT-
II.
2. Move the shift lever to the neutral , or the selector
lever to the P range.
3. Start the engine.
4. Use the MUT-
IIto activate the Actuator Test (item No.05)
while depressing the accelerator pedal fully. Check that
the engine speed should decrease gradually.
Caution
Activate the Actuator Test for three seconds.
Release the accelerator pedal immediately after the
Actuator Test is complete, or the engine speed will
rise.
NOTE
During the Actuator Test, the SC-ECU transmits the signal,
which requests no torque and wide open throttle, to the
engine-ECU or engine-A/T-ECU for three seconds.
WHEEL SPEED SENSOR (FR) CHECK
Refer to Basic Manual GROUP 35B - On-vehicle service.
VEHICLE SPEED SENSOR CHECK
Refer to Basic Manual GROUP 54A - Combination Meter.


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S
C -E C U
R EM OVA L AND IN STA LLA TIO N
C au tio n
W hen re m ovin g an d in sta llin g th e SC -E C U, do not le t it bum p ag ain st th e SR S-E C U. 5
±
1 N×
m H
eate r unit