1998 MITSUBISHI MONTERO wiring

DVOM, check voltage between ECU 22-pin connector terminal No. 35 and
ground. See Figs. 5-6. Battery voltage should exist in 4WD. Go to next
step.
3) If voltage is not as specified, check and repair
connectors and wiring harness between center differential lock
detection switch and ECU. See WIRING DIAGRAMS. Center differential
lock detection switch is located on side of transfer case. See Fig. 9.
If voltage is as specified, check and repair ECU 22-pin connector. If
connector is okay, replace ECU.
Fig. 9: Identifying 4WD Indicator Switch Location
Courtesy of Mitsubishi Motor Sales of America.
NOTE: When checking for short in ECU circuit, remove ECU connector
and ensure 4WD indicator light operates correctly. If 4WD
indicator light operates correctly, replace faulty ECU. If
4WD indicator light does not operate correctly, replace
faulty 4WD indicator control unit.
4) If no indicator lights come on, repair 4WD indicator power
circuit, or check for faulty 4WD indicator control unit. See 4WD
CONTROL UNIT under COMPONENT TESTS. If center differential light comes
on, regardless of position of transfer shift lever, check the
following:

* Check for short in center differential lock switch circuit.
* Check for faulty center differential lock switch.
* Check for short in ECU circuit or faulty ECU.
* Check for short in indicator control unit circuit or faulty
4WD indicator control unit.
Repair wiring harness or replace component as necessary. See
WIRING DIAGRAMS .
5) If 4WD indicator light does not come on with transfer
shift lever in "4H" position, repair wiring harness between 4WD
indicator control unit and center differential lock switch. Check for
faulty 4WD indicator control unit.
6) If 4WD indicator light does not come on with transfer
shift lever in "4H" position, repair wiring harness between 4WD
indicator control unit and free wheel engage switch. See
WIRING DIAGRAMS . Check ground wire at engage switch. Check for faulty
free wheel engage switch.
DTC 27: REAR DIFFERENTIAL LOCK DETECTION SWITCH (WITH
DIFFERENTIAL LOCK)
NOTE: DTC is set if ECU detects an open circuit in rear
differential lock detection switch system.
1) Start engine. Ensure rear differential indicator light
comes on when top of rear differential lock switch (located below
radio) is pushed. If indicator light comes on, go to step 3). If
indicator light does not come on, go to next step.
2) Turn engine off. Check wiring harness between rear
differential lock control unit and rear differential lock switch. See
WIRING DIAGRAMS . Check rear differential lock control unit power
circuit. See REAR DIFFERENTIAL CONTROL UNIT under COMPONENT TESTS. If
circuit is okay, replace rear differential lock control unit.
3) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between terminal No. 46 and ground. See Figs. 5-6.
When rear differential is locked, battery voltage should not be
present. When rear differential is unlocked, battery voltage should be
present. If voltage is as specified, go to next step. If voltage is
not as specified, repair connectors and related wiring harness between
ECU and rear differential lock switch. See WIRING DIAGRAMS.
4) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 27: REAR DIFFERENTIAL LOCK DETECTION SWITCH (WITHOUT
DIFFERENTIAL LOCK)
NOTE: DTC is set if ECU detects an interruption of battery voltage
at ECU terminal No. 46.
1) Check fuse No. 18 in main fuse block. If fuse is blown,
correct cause of blown fuse, and replace fuse. If fuse is okay, go to
next step.
2) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between terminal No. 46 and ground. See Figs. 5-6.
If battery voltage is present, go to next step. If battery voltage is
not present, check and repair connectors and related wiring harness
between ECU and fuse No. 18. See WIRING DIAGRAMS.
3) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 32: "G" SENSOR SYSTEM
NOTE: DTC is set if ECU detects "G" sensor output voltage less

than 0.5 volt or more than 4.5 volts, or an open or short
circuit in "G" sensor system.
1) Disconnect "G" sensor connector. Sensor is located on
bracket under center console, next to shifter. See Fig. 10. Connect
Special Tool (MB991348) between sensor and connector. Using a DVOM,
check voltage between sensor connector terminals No. 2 (Blue/White
wire) and No. 3 (Black/Red wire). Voltage should be 2.38-2.62 volts.
If voltage is as specified, reconnect sensor connector and go to step
3). If voltage is not as specified, leave special tool and DVOM
connected and go to next step.
2) Note top center position of sensor, and remove sensor. See
"G" SENSOR under REMOVAL & INSTALLATION . Secure sensor so that arrow
on sensor is facing straight down. Voltage should be 3.4-3.6 volts. If
voltage is specified, reinstall sensor and go to next step. If voltage
is not as specified, replace sensor.
3) Turn ignition off. Disconnect ECU 26-pin connector. Turn
ignition on. Check voltage between ECU 26-pin connector terminals No.
4 and 17. See Figs. 5-6. Voltage should be 2.4-2.6 volts. If voltage
is as specified, go to next step. If voltage is not as specified,
check and repair connectors and related wiring harness between ECU and
sensor. See WIRING DIAGRAMS .
4) Check and repair ECU 26-pin connector. If connector is
okay, replace ECU.
Fig. 10: Locating "G" Sensor
Courtesy of Mitsubishi Motor Sales of America.
DTC 33: STOPLIGHT SWITCH SYSTEM

NOTE: DTC is set if ECU detects stoplight switch stays on for 15
minutes or more, or an open circuit in stoplight switch
system.
1) Check if stoplights are functioning correctly. If
stoplights function correctly, go to next step. If stoplights do not
function correctly, check and repair stoplight circuit. See
WIRING DIAGRAMS.
2) Turn ignition off. Disconnect ECU 22-pin connector. Using
DVOM, measure voltage between ECU 22-pin connector terminal No. 34 and
ground while depressing brake pedal. See Figs. 5-6. If battery voltage
is present, go to next step. If battery voltage is not present, check
and repair connectors and related wiring harness between stoplight
switch and ECU. See WIRING DIAGRAMS.
3) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 41, 42 OR 43: SOLENOID VALVE CIRCUIT
NOTE: DTC sets if ECU senses that solenoid is on with no power
supplied, or off with power supplied.
1) Disconnect hydraulic unit connectors. Using ohmmeter,
check resistance between hydraulic unit connectors terminals No. 4 and
12, 5 and 12, and 6 and 12. See Fig. 11. Resistance should be 4.04-4.
54 ohms. If resistance is as specified, go to next step. If resistance
is not as specified, replace faulty hydraulic unit. See HYDRAULIC UNIT
under REMOVAL & INSTALLATION .
2) Check resistance between hydraulic unit connectors
terminals No. 1 and 12, 2 and 12, and 3 and 12. Resistance should be
8.04-8.59 ohms. If resistance is as specified, go to next step. If
resistance is not as specified, replace faulty hydraulic unit. See
HYDRAULIC UNIT under REMOVAL & INSTALLATION .
3) Turn ignition off. Disconnect ECU connectors. Check
continuity of each circuit between ECU connectors and hydraulic unit
connectors. See WIRING DIAGRAMS. If continuity exists, go to next
step. If continuity does not exist, check and repair connectors and
related wiring harness between ECU and hydraulic unit. See
WIRING DIAGRAMS .
4) Check continuity between hydraulic unit connector terminal
No. 12 and ABS relay box terminal No. 1. See Figs. 4 and 11. If
continuity exists, go to next step. If continuity does not exist,
check and repair connectors and related wiring harness between
hydraulic unit and ABS relay box. See WIRING DIAGRAMS.
5) Check and repair ECU connectors. If connectors are okay,
replace ECU.
Fig. 11: Identifying Hydraulic Unit Connector Terminals
Courtesy of Mitsubishi Motor Sales of America.
DTC 51: VALVE RELAY

NOTE: DTC is set if valve relay is removed or if no power is
supplied to relay.
1) Inspect ABS relay box. See Fig. 3. Replace ABS relay box
if needed. If ABS relay box is okay, go to next step.
2) Disconnect ABS relay box 8-pin connector. Turn ignition
on. Using a DVOM, check voltage between ABS relay box 8-pin harness
connector terminal No. 6 and ground. See Fig. 4. If battery voltage
exists, go to next step. If battery voltage does not exist, check and
repair wiring harness between ABS valve relay and fusible link No. 1.
See WIRING DIAGRAMS .
3) Disconnect ECU connectors. Check resistance between ECU
22-pin connector terminal No. 37 and ECU 26-pin connector terminal No.
26. Resistance should be 60-120 ohms. If resistance is as specified,
go to next step. If resistance is not as specified, check and repair
connectors and related wiring harness between ABS valve relay and ECU.
See WIRING DIAGRAMS .
4) Check continuity between ECU 22-pin connector terminal No.
48 and ground. If continuity exists, go to next step. If continuity
does not exist, check and repair wiring harness between ABS valve
relay and ECU. See WIRING DIAGRAMS.
5) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 53: MOTOR RELAY
NOTE: DTC is set when ECU detects motor relay on but motor does
not run, motor relay off but motor does not stop, or when
motor relay is faulty.
1) Using scan tool, perform hydraulic unit actuator test. If
motor is not operating, go to next step. If motor is still operating,
repair wiring harness between hydraulic unit and ECU. See
WIRING DIAGRAMS .
2) Inspect ABS relay box. See Fig. 3. Replace ABS relay box
if needed. If ABS relay box is okay, go to next step.
3) Disconnect ABS relay box 2-pin connector. Using DVOM,
check voltage between 2-pin connector terminal No. 11 and ground. See
Fig. 4 . If battery voltage is present, go to next step. If battery
volt age is not present, check and repair wiring harness between ABS
motor relay and fusible link No. 1. See WIRING DIAGRAMS.
4) Turn ignition off. Disconnect ECU connectors. Check
resistance between ECU 22-pin connector terminal No. 38 and 26-pin
connector terminal No. 26. Resistance should be 26-38 ohms. If
resistance is as specified, go to next step. If resistance is not as
specified, check and repair connectors and related wiring harness
between ABS motor and ECU. See WIRING DIAGRAMS.
5) Check resistance between ECU 22-pin connector terminal No.
49 and ground. Resistance should be 0.1-0.3 ohm. If resistance is as
specified, go to next step. If resistance is not as specified, check
and repair hydraulic unit motor ground connection or wiring harness
between ECU and hydraulic unit. See WIRING DIAGRAMS.
6) Check motor operation. Momentarily apply battery voltage
to hydraulic unit connector terminal No. 11. See Fig. 11. If motor
operates, go to next step. If motor does not operate, replace
hydraulic unit.
7) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
COMPONENT TESTS
4WD CONTROL UNIT

Fig. 15: Rear Differential Control Unit Pin Voltage Chart
Courtesy of Mitsubishi Motor Sales of America.
WHEEL SPEED SENSOR (WSS)
WSS Resistance Test
1) Before testing WSS resistance, ensure pole piece-to-WSS
tip is clean. Check WSS pole piece for damage. If pole piece is
damaged, replace WSS.
2) Disconnect WSS connector. Inspect WSS wiring harness for
broken and pinched wires. See WIRING DIAGRAMS. Repair harness as
necessary. If harness is okay, go to next step.
3) Using ohmmeter, check resistance across WSS terminals.
Resistance for front WSS should be 1170-1350 ohms. Resistance for rear
WSS should be 1300-1500 ohms. If resistance is as specified, go to
GROUND CIRCUIT TEST. If resistance is not as specified, replace WSS.
Ground Circuit Test
Disconnect WSS wiring harness connector. Check resistance
between each WSS terminal and WSS housing. Resistance should be more
than 100,000 ohms. If resistance is not as specified, replace WSS.
REMOVAL & INSTALLATION
ELECTRONIC CONTROL UNIT (ECU)
Removal & Installation
1) ECU is located behind right rear quarter panel trim. See
Fig. 16 . Disconnect negative battery cable. Remove quarter panel
mounti ng screws and trim clip.
2) Carefully remove quarter panel trim. Disconnect ECU wiring
harness connector. Remove ECU mounting bolts/nuts and ECU. To install,
reverse removal procedure.

Fig. 16: Locating Electronic Control Unit (ECU)
Courtesy of Mitsubishi Motor Sales of America.
"G" SENSOR
CAUTION: DO NOT turn "G" sensor upside-down or lay unit on its side.
DO NOT drop "G" sensor. DO NOT disassemble unit. Replace "G"
sensor as an assembly.
Removal & Installation
Sensor is located under center console, near shifter. See
Fig. 10 . Remove center console assembly. Disconnect sensor wiring
harnes s connector. Remove sensor. To install, reverse removal
procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS.
HYDRAULIC UNIT
Removal
Remove brakelines from hydraulic unit. Remove ABS relay box
cover. See Fig. 3. Disconnect ground wire and wiring harness
connectors from hydraulic unit. Remove hydraulic unit retaining nuts.
Carefully remove hydraulic unit.
Installation
To install, reverse removal procedure. Install hydraulic unit
brakelines. Ensure brakelines are installed in correct location. See
Fig. 17. Bleed brake system. See BLEEDING BRAKE SYSTEM.

Removal & Installation
Disconnect WSS connector. Remove WSS bolts. Remove WSS from
vehicle. To install, reverse removal procedure. Sensors are not
interchangeable. Adjust wheel WSS-to-rotor gap. See WHEEL SPEED SENSOR
(WSS) under ADJUSTMENTS. To complete installation, reverse removal
procedure. Tighten WSS bolts to specification. See
TORQUE SPECIFICATIONS .
WHEEL SENSOR ROTOR
Removal & Installation
Remove brake disc. Remove disc assembly. Remove wheel
bearings. Remove axle hub. Remove bolts attaching sensor rotor to hub
assembly. To install, reverse removal procedure.
OVERHAUL
HYDRAULIC UNIT
DO NOT attempt to overhaul or disassemble hydraulic unit. If
hydraulic unit is defective, replace entire assembly.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS








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Application INCH Lbs. (N.m)\
"G" Sensor Mounting Bolt ................................. 80 (9.0)\
Wheel Speed Sensor (WSS) Bolt .................... 84-120 (9.5-14.6\
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WIRING DIAGRAMS