TROUBLE DIAGNOSIS
TF-57
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3.INSPECTION USING 4WD MODE CHANGE-OVER SWITCH
lOn data monitor screen of the CONSULT-II, check 4WD mode switch.
lCheck if the display changes from ## to 2WD mode when the 2WD switch is pressed.
lCheck if the display changes from ## to AUTO mode when the AUTO switch is pressed.
lCheck if the display changes from ## to LOCK mode when the LOCK switch is pressed.
OK or NG
OK >> No malfunction detected.
NG >>
lNot in AUTO mode. (in 2WD or LOCK mode)
Countermeasure: Slightly depress the accelerator pedal and check that the operation mode
changes to LOCK mode.
lCheck circuit between 4WD mode switch harness connector M39 terminal No.1 (BR) and
4WD control unit harness connector E122 terminal No. 27 (BR).
(AUTO mode is not available because a malfunction is present in the 2WD mode harness.)
NOTICE:
Mechanism of 4WD mode change-over
l2WD mode: Operation changes to 2WD mode when 4WD control unit harness connector E122
terminal No. 27 (BR) is shorted to ground.
lAUTO mode: Operation changes to AUTO mode when 4WD control unit harness connector
E122 terminals No. 27 (BR) and No. 26 (L) is shorted to ground.
lLOCK mode: Operation changes to LOCK mode when 4WD control unit harness connector
E122 terminal No. 26 (L) is shorted to ground.
4WD MODES CANNOT BE SWITCHED AFTER ENGINE IS STARTED
1.INSPECTION USING 4WD MODE CHANGE-OVER SWITCH
lDrive modes cannot be switched after the engine is started.
lOn data monitor screen of the CONSULT-II, check 4WD mode switch.
lCheck if the display changes from ## to 2WD mode when the 2WD switch is pressed.
lCheck if the display changes from ## to AUTO mode when the AUTO switch is pressed.
lCheck if the display changes from ## to LOCK mode when the LOCK switch is pressed.
OK or NG
OK >> No malfunction detected.
NG >>
lCONSULT-II display does not change from ## when the 2WD switch is pressed. Check harness
of the 2WD switch.
lCONSULT-II display does not change from ## when the AUTO switch is pressed. Check har-
ness of the 2WD switch and LOCK switch.
lCONSULT-II display does not change from ## when the LOCK switch is pressed. Check har-
ness of the LOCK switch.
lPerform 4WD mode change-over switch inspection.
WHILE DRIVING, 4WD WARNING LAMP FLASHES RAPIDLY. (WHEN IT FLASHERS FOR
APPROX. ONE MINUTE, THEN DOES NOT ILLUMINATE.)
lWhile driving, 4WD warning lamp flashes rapidly. (when it flashes for approx. one minute, then does not
illuminate.)
Rapid flashing: 2 times/second
This phenomenon protects drivetrain parts when a heavy load is applied to the electronically controlled
coupling and multiple disc clutch temperature increases. It is not a malfunction.
When the difference of diameters by or with the front and rear wheel with AUTO mode the shift switch
occasionally changes to LOCK mode automatically. This is not a malfunction.
When the difference of revolution speed between the front and rear wheel with AUTO mode, the shift
switch occasionally changes to LOCK mode automatically. This is not a malfunction.
TF-58
TROUBLE DIAGNOSIS
WHILE DRIVING, 4WD WARNING LAMP FLASHES SLOWLY. (WHEN IT CONTINUES TO ILLU-
MINATE UNTIL ENGINE TURNS OFF.)
1. Check using the data monitor function of the CONSULT-II.
lPerform inspection with the data monitor function of the CONSULT-II.
lCheck if the value of IMPROPER SIZE TIRE MONITOR is 8 mm (0.31 in) or more.
lStop the engine. Restart the engine and drive the vehicle at 20 km/h (12 MPH) or faster for approxi-
mately 200 seconds. Confirm the 4WD warning lamp flashes slowly.
(Check if the value of IMPROPER SIZE TIRE MONITOR is 8 mm (0.31 in) or more.)
When the tire size is normal, the value of IMPROPER SIZE TIRE MONITOR will change from 8 mm
(0.31 in) or more to 0 to 4 mm (0 to 0.16 in) (normal condition) after the vehicle is driven 20 km/h (12
MPH) or faster for approximately 5 seconds.
2. Tire inspection
lInspection of tire pressure
lWear condition
lCheck size of the front and rear tires. (No excessive difference should be observed.)
VEHICLE DOES NOT ENTER 4WD MODE EVEN THOUGH 4WD WARNING LAMP IS OFF.
1. Check using the data monitor function of the CONSULT-II.
Perform inspection by the data monitor function of the CONSULT-II.
–Check if the vehicle operation changes to 2WD, AUTO, and LOCK modes.
–Check current supplied to the 4WD solenoid valve in AUTO mode.
2. Check using the active test function of the CONSULT-II.
Using active test mode of CONSULT-II, supply current to the 4WD solenoid valve and check that the mon-
itor current becomes close to this supply current.
lThe 4WDcontrol unit is normal when the difference between 4WD solenoid valve current and the monitor
current is within±10%.
It is necessary to inspect the electronically controlled coupling assembly.
TIGHT-CONER BRAKING SYMPTOM OCCURS WHEN THE VEHICLE IS STARTED IN AUTO
WARNING LAMP REMAIN OFF).
1.THROTTLE POSITION SENSOR AND HARNESS INSPECTION
Check accelerator pedal stroke.
OK or NG
OK >> Perform self-diagnosis again.
NG >> Malfunctioning throttle position sensor harness
4WD ACTUATOR RELAY (4WD SOLENOID ACTUATOR RELAY) TURNS ON/OFF FREQUENTLY
1.SELF-DIAGNOSIS RESULT IS 4WD ACTUATOR RELAY (4WD SOLENOID ACTUATOR RELAY) ON
ERROR AND OFF ERROR.
Is self-diagnosis result [ON error and OFF error]?
OK or NG
OK >> GO TO 2.
NG >> Repair or replace as necessary.Accelerator pedal not
depressed:Approx. 0A
Accelerator pedal
depressed:Approx. 2.8A
Example) Monitor value becomes approx. 1A for 4WD solenoid current 1A setting.
