1998 MITSUBISHI MONTERO diagram

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.

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

Fig. 18: Anti-Lock Brake System (ABS) Wiring Diagram (1997 Montero)\

Fig. 19: Anti-Lock Brake System (ABS) Wiring Diagram (1998 Montero)\

Once repairs have been performed, DTCs must be cleared from
TCM memory. DTCs may be cleared by disconnecting negative battery
cable for 10 seconds or more. Reconnect cable and ensure DTCs have
been cleared. Start engine and warm to normal operating temperature.
Run engine at idle for 10 minutes. DTCs may also be cleared using scan
tool. Refer to manufacturer's instruction manual.
DIAGNOSTIC TESTS
NOTE: For terminal and wire color identification, see WIRING
DIAGRAMS.
DTC 11: THROTTLE POSITION (TP) SENSOR
For diagnosis and testing information, see appropriate SELF-
DIAGNOSTICS article in ENGINE PERFORMANCE section. If TP sensor is
okay, check wiring harness and connectors between TP sensor and TCM.
Repair if necessary. If wiring harness and connectors are okay,
replace TCM.
DTC 15 & 16: OPEN OR SHORT IN OIL TEMPERATURE SENSOR CIRCUIT
1) Test oil temperature for proper operation. See OIL
TEMPERATURE SENSOR under COMPONENT TESTING. If oil temperature sensor
is okay, check wire harness, connectors and ground circuit for poor
connections or damage. Go to next step.
2) If wire harness and connectors are okay, check DTCs again
and verify code No. 15 or No. 16 still exists. If either code still
exists, replace TCM.
DTC 21 & 22: SHORT OR OPEN IN IGNITION SIGNAL CIRCUIT
1) Using an external tachometer, verify vehicles' tachometer
is operating accurately. If tachometer is incorrect, check ignition
coil and ignition power transistor and circuits for malfunction. See
appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section.
2) If tachometer is okay, check TCM wire harness connector
for poor connection. If wire harness is okay, recheck DTCs. If codes
reappear check wire harness between ignition power transistor and TCM.
If wire harness is okay, replace TCM.
DTC 23 & 24: OPEN OR SHORT IN SIGNAL LINE (ECT) FROM ECM TO
TCM
Check wire harness, connectors and ground circuit for poor
connections or damage. Go to next step. If wire harness and connectors
are okay, check DTCs again and verify code No. 23 or No. 24 still
exists. If either code still exists, replace TCM.
DTC 29 & 30: SHORT OR OPEN IN PARK/NEUTRAL POSITION (PNP)
SWITCH CIRCUIT
1) Check PNP switch for correct operation. See. If PNP switch
is okay, disconnect switch connector and measure voltage between
harness connector terminal No. 1 and ground.
2) If battery voltage does not exist, check wire harness and
connectors. See WIRING DIAGRAMS. If battery voltage exists, check wire
harness and connectors between PNP switch and TCM. If wire harness is
okay, replace TCM.
DTC 31: INPUT SPEED SENSOR