2) Disconnect ECU 26-pin connector. Check resistance between
specified ECU connector terminals. See
WHEEL SPEED SENSOR OUTPUT CIRCUIT IDENTIFICATION table. See Figs. 5-6.
Resistance for front sensors should be 1170-1350 ohms. Resistance for
rear sensors should be 1300-1500 ohms. If resistance is as specified,
go to next step. If resistance is not as specified, check and repair
connectors and related wiring between ECU and suspect sensor. See
WIRING DIAGRAMS .
3) Raise and support vehicle. Disconnect ECU connectors.
Using DVOM, backprobe specified ECU connector terminals. See
WHEEL SPEED SENSOR OUTPUT CIRCUIT IDENTIFICATION table. See Figs. 5-6.
Check voltage between each harness connector terminal while rotating
wheel at 1/2 to one rotation per second. If pulse voltage is 70 mV or
more, go to step 8). If voltage is not as specified, go to next step.
4) Inspect condition of suspect speed sensor. Ensure tip of
speed sensor is clean. If speed sensor is okay, go to next step.
5) Disconnect sensor connector. Using DVOM, check resistance
across sensor terminals. Resistance for front sensors should be 1170-
1350 ohms. Resistance for rear sensors should be 1300-1500 ohms. If
resistance is as specified, go to next step. If resistance is not as
specified, replace sensor.
6) Remove sensor. Check resistance between each sensor
terminal and sensor body. If resistance is 100,000 ohms or more, go to
next step. If resistance is not as specified, replace sensor.
7) Inspect condition of toothed rotor. Check for broken or
deformed teeth. If toothed rotor is okay, go to next step.
8) Check ECU connectors. Repair connectors as needed. If
connectors are okay, replace ECU.
DTC 25: FREE WHEEL ENGAGE SWITCH
NOTE: DTC sets if ECU detects an open circuit in free wheel engage
switch.
1) Start engine. Ensure 4WD indicator light operates
correctly when transfer shift lever is moved to desired 4WD positions.
If indicator light operates correctly, go to step 3). If indicator
light does not operate correctly, go to next step.
2) Turn engine off. Check wiring harness between 4WD
indicator control unit (located behind radio) and free wheel engage
switch (located on right side of front differential housing, near
carrier assembly). If circuit is okay, replace 4WD indicator control
unit.
3) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between ECU 22-pin connector terminal No. 45 and
ground. See Figs. 5-6. In 2WD, battery voltage should exist. Battery
voltage should not exist in 4WD. If voltage is as specified, go to
next step. If voltage is not as specified, check and repair connectors
and wiring harness between free wheel engage switch and ECU. See
WIRING DIAGRAMS .
4) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 26: CENTER DIFFERENTIAL LOCK DETECTION SWITCH
NOTE: DTC sets if ECU detects an open circuit in center
differential lock detection switch system.
1) Start engine. Ensure 4WD indicator light operates
correctly when transfer shift lever is moved to desired 4WD positions.
If indicator light does not operate correctly, go to step 4). If
indicator light operates correctly, go to next step.
2) Disconnect ECU 22-pin connector. Turn ignition on. Using
* 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
Remove radio and remove 4WD control unit. Disconnect control
unit harness connector. Backprobe harness connector. Check voltage
between each individual terminal and ground terminal No. 8 (Black
wire). See Figs. 12 and 13. If after all tests have been completed
system is not operating properly, substitute 4WD control unit with
known-good unit and retest.
Fig. 12: Identifying 4WD Control Unit Connector
Courtesy of Mitsubishi Motor Sales of America.
Fig. 13: 4WD Control Unit Pin Voltage Chart
Courtesy of Mitsubishi Motor Sales of America.
4WD INDICATOR SWITCHES
* PLEASE READ THIS FIRST *
WARNING: Deactivate air bag system before performing any service
operation. See AIR BAG RESTRAINT SYSTEMS article. Do not
apply electrical power to any component on steering column
without first deactivating air bag system. Air bag may
deploy.
ACTUATOR
Removal & Installation
Disconnect cruise control cable from link. Disconnect
actuator wiring connector. Remove vacuum pump and vacuum pump bracket.
Remove actuator and actuator bracket. To install, reverse removal
procedure.
CRUISE CONTROL ECU
Removal & Installation
Cruise control ECU is located behind center of dash panel.
Remove center trim panel and radio or radio plug bezel. Remove control
unit. To install, reverse removal procedure.
CRUISE CONTROL SWITCH
Removal & Installation
Remove lower steering column cover. Disconnect electrical
connectors. Remove screws attaching cruise control switch to steering
column. Remove switch. To install, reverse removal procedure.
INSTRUMENT CLUSTER
Removal & Installation
Disconnect negative battery cable. Remove cluster cover.
Disconnect speedometer cable. Remove instrument cluster. To install,
reverse removal procedure.
WIRING DIAGRAMS
1) Start and run engine at 2000 RPM. Ensure battery is fully
charged. Turn defogger switch to ON position. Using a voltmeter, check
voltage at center section of each defogger grid filament.
2) If voltage is about 6 volts, grid filament is okay. If
voltage is about 12 volts, an open is present in negative circuit.
Move probe slowly toward negative terminal to determine location of
open circuit.
3) If voltage is zero volts, an open is present in positive
circuit. Move probe slowly toward positive terminal to determine
location of open circuit. Repair grid as necessary. See
GRID FILAMENT REPAIR under ON-VEHICLE SERVICE.
ON-VEHICLE SERVICE
GRID FILAMENT REPAIR
Clean broken wire tips thoroughly. Place masking tape along
both sides of broken wire. See Fig. 8. Apply Repair Paste (DuPont
4817) to broken section of grid. Remove masking tape after paste has
dried. Wait 24 hours before using defogger.
Fig. 8: Repairing Rear Defogger Grid Element
REMOVAL & INSTALLATION
DEFOGGER SWITCH
Removal & Installation (Diamante)
Defogger switch is integral with A/C system ECU. To remove
A/C ECU, remove center console. Remove audio panel. Remove radio.
Remove A/C ECU. To install, reverse removal procedure.
Removal & Installation (Eclipse)
Remove upper stoppers from glove compartment. Drop down glove
compartment. From glove compartment opening, reach behind center air
outlet assembly and disconnect harness connectors to switches. Release
metal clips from center air outlet assembly. Remove center air outlet.
Remove defogger switch from center air outlet. To install, reverse
removal procedure.
Removal & Installation (Galant)
At heater unit, remove center air outlet cool air by-pass
lever cable from damper lever. To remove center air outlet, push
springs at bottom of center air outlet upward. Outlet is located above
radio. Remove switch from center air outlet. To install, reverse
removal procedure. Turn cool air by-pass lever on outlet fully upward.
Pull air by-pass lever fully downward and install cool air by-pass
lever cable to damper lever.
Removal & Installation (Mirage)
Remove driver-side lower dash panel. Remove center console
assembly and foot distribution duct. Disconnect rear window defogger
switch harness connector. Remove switch. To install, reverse removal
procedure.
Removal & Installation (Montero)
Remove defogger switch by prying switch off instrument
cluster bezel. Disconnect wiring harness from defogger switch. Remove
switch. To install, reverse removal procedure.
Removal & Installation (Montero Sport)
Remove instrument cluster bezel. Bezel is held in by metal
clips. Disconnect wiring harness from defogger switch. Remove switch
from behind bezel. To install, reverse removal procedure.
Removal & Installation (3000GT)
Remove knee protector. Remove steering column upper and lower
covers. Remove instrument cluster bezel. Disconnect wiring harness
from defogger switch. Remove defogger switch. To install, reverse
removal procedure.
WIRING DIAGRAMS
DIFFERENTIAL LOCK - REAR
1998 Mitsubishi Montero
1997-98 DRIVE AXLES
Mitsubishi Rear Differential Lock
Montero, Montero Sport
DESCRIPTION & OPERATION
The rear differential lock system is designed to be used only
when low-speed wheel spin occurs in a ditch, or on a slippery or
uneven surface. The indicator light will blink when switch is turned
on as system completes locking operation. After the differential is
locked, the light will stop blinking and remain on.
The rear differential lock system will not lock with vehicle
in 4H or 2H position, and if vehicle speed is greater than 7 MPH.
Vehicle speed should be maintained at less than 12 MPH during rear
differential lock operation.
NOTE: The Anti-lock Brake System (ABS) does not operate when the
rear differential is locked. It is normal for the ABS
warning light to be on at this time.
COMPONENT LOCATIONS
Rear Differential Lock Air Pump
Air pump is located under left side of rear seat.
Rear Differential Lock Control Unit
Control unit is located under left side lower quarter trim
panel in rear compartment.
Rear Differential Lock Switch
Lock switch is located on lower center of instrument panel,
below radio.
Rear Differential Lock Detection Switch
Lock detection switch is located on rear differential
carrier.
TROUBLE SHOOTING
INDICATOR LIGHT FLASHES WHEN LOCK SWITCH IS TURNED ON
If vehicle speed is greater than 7 MPH, reduce speed to less
than 3 MPH. If vehicle speed is less than 7 MPH, rotate steering wheel
to right and left to reset light.
INDICATOR LIGHT FLASHES WHEN LOCK SWITCH IS TURNED OFF
If indicator flashes after lock switch is turned off, depress
and release accelerator several times while driving straight ahead to
reset light.
TESTING
REAR DIFFERENTIAL LOCK AIR PUMP
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
CAUTION: When removing or installing floor console, DO NOT allow any
impact or shock to Supplemental Restraint System Electronic
Control Unit (SRS-ECU).
FRONT HEATER UNIT & HEATER CORE
Removal
1) Deactivate air bag system. See AIR BAG RESTRAINT SYSTEM
article. Remove front and rear floor consoles. Remove hood release
handle. Remove fuel door release handle. Remove knee protector and
support brackets. Remove speaker covers.
NOTE: On A/T models, when removing front floor console, set A/T
selector lever in "L" position.
2) Remove glove box door stop, glove box and glove box frame.
Remove passenger-side air bag module. Remove heater control panel
cover. Remove heater control panel and radio. Remove plug from
instrument cluster cover. Remove instrument cluster cover and
instrument cluster.
3) Remove steering column cover. Remove clock or plug. Remove
side defroster covers. Remove side mirror control switch. Remove front
speakers.
4) Remove rheostat, rear wiper/washer switch, and door lock
switch. Disconnect ventilation control cable and harness connector.
See Fig. 9. Remove instrument panel. See INSTRUMENT PANEL. Drain
coolant and disconnect heater hoses from heater unit.
5) Remove shower ducts, lap duct, joint duct and center duct.
See Fig. 1 . Remove center reinforcement. Remove heater unit. Remove
distribution duct. Remove heater core.
Installation
Install heater core, distribution duct, heater unit and
center reinforcement. Install remaining ducts in reverse order of
removal. Install instrument panel. Tighten steering column bolts to 16
ft. lbs. (22 N.m). Install and adjust ventilation control cable. See
ADJUSTMENTS . To complete installation, reverse removal procedure. Add
coolant and check for leaks.
INSTRUMENT PANEL
Removal & Installation
Remove instrument panel components and then instrument panel,
in order listed on appropriate illustration. See Fig. 9. To install,
reverse removal procedures.