Page 506 of 801

YH4
GRAND
VITARA
7E-4 DIFFERENTIAL (FRONT)
Components and Functions
ComponentFunction
4WD switch
When the transfer shift lever is shifted to 4L or 4H position, this switch turns ON
and causes the 4WD control system to turn ON, unless it is shifted to N or 2H
within 1 second.
ECM or PCM
When the 4WD switch turns ON [unless it turns OFF within 1 second], this com-
ponent actuates the pump assembly. If the pressure in the air pump assembly
fails to increase higher than the set level even after the pump motor has run more
than 10 seconds, this component stops the motor to protect it.
Air pump assembly
Pump motor
Release valve
Pressure switchThe air pump assembly consists of a pump motor, release valve and a pressure
switch.
Pump motor:
Produces positive pressure which actuates the actuator.
Release valve:
Closes when transfer shift lever is shifted to 4H or 4L so that the positive pressure
is applied to the actuator, and opens when N or 2H to release the pressure to the
atmosphere.
Pressure switch:
Turns ON and OFF depending on the pressure level in the pump assembly
(whether higher or lower than the set pressure level). ECM or PCM detects the
pressure level through this switch.
Differential case assembly
Free axle hub
Axle lock clutch
ActuatorThe free axle hub, axle lock clutch and actuator are installed in the differential
left case. The positive pressure produced in the air pump assembly is applied
to the actuator which then pushes the axle lock clutch to be engaged with the free
axle hub. In this state, the drive force is transmitted to the front axle, resulting in
the 4WD mode.
When the actuator is free from the positive pressure [when it is under the atmo-
spheric pressure], the axle lock clutch is pushed back by the return spring force
and cannot be engaged with the free axle hub, resulting in the 2WD mode.
ª4WDº indicator lampIt lights up when 4WD control system is in the 4WD mode.
Page 507 of 801

YH4
GRAND
VITARA
DIFFERENTIAL (FRONT) 7E-5
DIAGNOSIS
DIAGNOSIS TABLE
Differential Assembly
ConditionPossible CauseCorrection
Gear noiseDeteriorated or water mixed lubricant
Inadequate or insufficient lubricant
Maladjusted backlash between bevel
pinion and gear
Improper tooth contact in the mesh between
bevel pinion and gear
Loose bevel gear securing bolts
Damaged side gear(s) or side pinion(s)Repair and replenish
Repair and replenish
Adjust
Adjust or replace
Replace or retighten
Replace
Bearing noise(Constant noise) Deteriorated or water
mixed lubricant
(Constant noise) Inadequate or insufficient
lubricant
(Noise while coasting) Damaged bearing(s)
of bevel pinion
(Noise while turning) Damaged diff. side
bearing(s) or axle bearing(s)Repair and replenish
Repair and replenish
Replace
Replace
Oil leakageWorn or damaged oil seal
Excessive oil
Loose differential carrier boltsReplace
Adjust oil level
Replace or retighten
2WD / 4WD
switching errorDefective actuator
Abnormality in 4WD control systemReplace
Inspect referring to ª4WD
CONTROL SYSTEM DIAG-
NOSTIC FLOW TABLEº.
4WD Control System Diagnostic Flow Table
Before performing the trouble diagnosis, check that the transfer and front differential are in good condition and
there is no air leakage from air hoses and the actuator. Refer to ªON-VEHICLE SERVICEº in this section for air
leakage.
[NOTES ON SYSTEM CIRCUIT INSPECTION]
Be sure to read ªPrecautions for Electrical Circuit Serviceº in Section 0A before circuit inspection and observe
what is written there.
For system circuit, refer to the figure of ªGENERAL DESCRIPTIONº in this section.
For terminal arrangement, refer to ª4WD Control Circuit Inspectionº in this section.
Page 512 of 801

YH4
GRAND
VITARA
7E-10 DIFFERENTIAL (FRONT)
1. Plugged hose
2. Adjusting screw
3. Pipe (to air pump assembly)
4. Hose (to differential carrier)
5. Differential housing
4 5
INSPECTION
4WD Control System
1) Install special tool to air hose connecting between air pump as-
sembly and differential (actuator) as shown in figure. Tighten ad-
justing screw of special tool as far as it stops. Close air check
side opening by using fuel hose as blind plug.
Special Tool
(A): 09918-18110
(B): 09367-04002
NOTE:
Use care not to bend any part of hose.
2) Turn ON ignition switch and shift transfer lever from 2H to 4H
range.
3) Check that motor starts running (a sound can be heard) within
1 second and it stops when gauge of special tool indicates speci-
fied pressure value.
Check also for air leakage.
Pressure specification:
30.0 ± 45.0 kPa (0.30 ± 0.45 kg / cm
2, 4.25 ± 6.40 psi)
4) Check that pressure value indicated on gauge of special tool
drops as soon as transfer lever is shifted to 2H position.
5) Start motor by shifting transfer lever to 4H position again. Loos-
en adjusting screw to lower pressure value on gauge. Motor
should start to run again and stop in about 4 seconds.
6) With the adjusting screw of special tool loosened, shift transfer
shift lever to N or 2H position and then 4L or 4H position.
Pump motor should stop about 10 seconds after motor starts to
run.
Page 513 of 801

YH4
GRAND
VITARA
DIFFERENTIAL (FRONT) 7E-11
1. Differential housing
2. Adjusting screw
3. To air compressor
Actuator
1) Disconnect air hose from pump assembly and install special tool
to air hose as shown in figure. Loosen adjusting screw of special
tool.
Special Tool
(A): 09918-18110
2) Connect compressor air hose to special tool.
Blow air and turn adjusting screw to obtain specified pressure.
Specified pressure: 30.0 kPa (0.3 kg / cm
2, 4.25 psi)
CAUTION:
Do not apply a pressure exceeding 200 kPa (2.0 kg / cm
2,
28.4 psi) which may cause damage to diaphragm.
3) With the vehicle lifted so that both of the front wheels are off the
ground, turn one of the front wheels by hand and check the other
wheel, which should act as described below.
When the pressure from compressor is applied to actuator:
The other front wheel should turn in the direction opposite to
the wheel being turned by hand.
When the pressure from compressor is not applied to actuator:
The other front wheel should remain stationary while the wheel
pushed by hand is turning.
If the result is not satisfactory, inspect differential assembly. Re-
fer to ªINSPECTIONº of SECTION 7E in UNIT REPAIR MANU-
AL.
Page 534 of 801
YH4
GRAND
VITARA
1. Headlight leveling switch
2. Headlight leveling unit (actuator)
3. Headlight
4. Headlight leveling unit shaft
Switch
PositionHeadlight beam
down angle
0 ÐÐÐ
1 0.624
2 1.243
3 1.867
4 2.479
LIGHTING SYSTEM 8B-3
HEADLIGHT WITH LEVELING SYSTEM (IF EQUIPPED)
Page 535 of 801

YH4
GRAND
VITARA
8B-4 LIGHTING SYSTEM
DIAGNOSIS
NOTE:
Fuse name (ª º) in the table below is shown on the fuse box cover (Hard Top Model) or the junction box
(Canvas Top Model).
HEADLIGHTS
TroublePossible causeCorrection
Only one light does not
lightBulb blown
Headlight L or R fuse blown
Socket, wiring or grounding faultyReplace bulb
Replace fuse to check for short
Repair
Headlights do not lightHeadlight L and R fuses blown
Lighting and dimmer switch faulty
Defective light relay
Wiring or grounding faultyReplace fuses to check for short
Replace switches
Replace light relay
Repair
Only one beam (ªHiº or
ªLoº) does not lightBulb blown
Lighting or dimmer switch faultyReplace bulb
Replace switch
HEADLIGHTS WITH LEVELING SYSTEM (IF EQUIPPED)
TroublePossible causeCorrection
Both headlights do not
moveªTURN / BACKº fuse blown (Hard Top Model)
ªTRNº fuse blown (Canvas Top Model)
Leveling switch faulty
Supply voltage too lowReplace fuse to check for short
Replace switch
Recharge or replace battery
One of headlights (either
Right or Left) does not
moveSocket, wiring or grounding faulty
Actuator faulty
Vehicle body around headlight deformed
Headlight ass'y itself deformedRepair
Replace actuator
Repair body
Replace headlight ass'y
TURN SIGNAL AND HAZARD WARNING LIGHTS
TroublePossible causeCorrection
Flash rate high or one side
only flashesIncorrect bulb
One of light bulbs burnt out
Turn signal / hazard warning relay faulty
Open circuit or high resistance existing
Replace bulb
Replace
Replace relay
RepairOen circuit or high resistance existing
between turn signal / hazard warning
switch and lights on one side
Wiring or grounding faulty
Re air
Repair
No flashingªTURN / BACKº and / or ªHAZARDº fuse(s)
blown (Hard Top Model)
ªTRNº and / or ªHAZº fuse(s) blown
(Canvas Top Model)
Open circuit or high resistance existing
between battery and switch
Turn signal / hazard relay faulty
Combination switch or hazard switch faulty
Wiring or grounding faultyReplace fuse(s) to check for
short
Check bulb and check circuit
Replace relay
Replace switch
Repair
Flash rate lowSupply voltage too low
Turn signal / hazard relay faultyCheck charging system
Replace relay
Page 538 of 801

YH4
GRAND
VITARA
LH steering vehicle shown
X-X:Horizontal center line of headlight bulbs
A-A:Vertical center line of left headlight bulb
B-B:Vertical center line of right headlight bulb1. Screen
2. For right / left adjustment
3. For up / down adjustment
(for vehicle without leveling system)
4. For up / down adjustment
(for vehicle with leveling system)
5. Headlight leveling actuatorHOT
SPOT LH. HEADLIGHT RH. HEADLIGHT
LIGHTING SYSTEM 8B-7
BULB REPLACEMENT
WARNING:
Don't touch when the bulb is hot.
1) Disconnect negative cable at battery.
2) Disconnect harness from bulb.
3) Remove socket cover and bulb.
4) Replace bulb and install in reverse removal procedure.
HEADLIGHT AIMING WITH SCREEN
NOTE:
Unless otherwise obligated by local regulations, adjust
headlight aiming according to following procedure.
After replacing headlight, be sure to perform its aiming.
When inspecting and adjusting headlight with leveling sys-
tem, make sure to set the leveling switch to ª0º position with
IG switch ON.
Before adjustment, make sure the following.
a) Place vehicle on a flat surface in front of blank wall as below
ahead of headlight surface.
Clearance ªaº: 10 m (32.8 ft)
b) Adjust air pressure of all tires to a specified value respectively.
c) Bounce vehicle body up and down by hand to stabilize suspen-
sion.
d) Carry out one driver aboard.
Driver's weight: 75 kg (165 lb)
Adjustment
1) Check to see if hot spot (high intensity zone) of each main (low)
beam axis falls as illustrated.
Clearance ªHº: Approx. 130 mm (5.15 in.)
2) If headlight aiming is not set properly, align it to specification by
adjusting aiming screw and aiming gear.
Page 539 of 801
YH4
GRAND
VITARA
8B-8 LIGHTING SYSTEM
HEADLIGHTS WITH LEVELING SYSTEM
(IF EQUIPPED)
LEVELING SWITCH
INSPECTION
To check the switch operation, substitute it with a new one. If proper
operation is obtained, it means the switch is defective.
Replace it with a new one.
LEVELING ACTUATOR
INSPECTION
All headlight system couples connected including leveling actuator
and switch, and at Ignition switch ON, listen to the leveling actuator
sound on both actuators according to the movement of the leveling
switch. If no sound is heard with the movement of the leveling
switch, replace headlight assembly.