YH4
GRAND
VITARA
7B1-4 AUTOMATIC TRANSMISSION (4 A / T)
ItemSpecifications
Torque
conver-
terType
Stall torque ratio3-element, 1-step, 2-phase type (with TCC (lock-up)
mechanism)
2.4 (G16 engine) 2.0 (J20 engine) 1.9 (H25 engine)
Oil
pumpType
Drive systemTrochoid type oil pump
Engine driven
TypeForward 4-step, reverse 1-step planetary gear type
Shift position
ªPº range Gear in neutral, output shaft fixed,engine start
ªRº range Reverse
ªNº range Gear in neutral, engine start
ªDº range Forward 1st 2nd 3rd 4th (O / D)
(O / D ON) automatic gear change
ªDº range Forward 1st 2nd 3rd
(O / D OFF) automatic gear change
ª2º range (Normal mode) Forward 1st 2nd 3rd automatic gear
change
(Power mode) Forward 2nd 3rd automatic gear
change and fixed at 2nd gear
ªLº range Forward 1st 2nd 3rd reduction, and fixed at 1st gear
GearEngine typeG16 engineJ20 / H25 engines
change
device1st (low gear)2.8262.826device2nd (second gear)1.4931.493
Gear3rd (top gear)1.0001.000Gear
ratio4th (overdrive
4th gear)0.7300.689
Reverse (reverse
Reverse gear)2.7032.703
Control elements
Wet type multi-disc clutch 3 sets. . . . . . . . . .
Wet type multi-disc brake 4 sets. . . . . . . . . .
One-way clutch 3 sets. . . . . . . . . . . . . . . . . . .
TransferHi: 1.000 Lo: 1.816 (4WD model only)
Final gear reduction
ratio (Differential)5.125 (G16 engine) 4.875 (J20 / H25 engines)
Lubrica-
tionLubrication systemForce feed system by oil pump
CoolingCooling systemRadiator assisted cooling (water-cooled)
Fluid usedAn equivalent of DEXRONIII
YH4
GRAND
VITARA
AUTOMATIC TRANSMISSION (4 A / T) 7B1-23
User name: Model: VIN:
Date of issue: Date of Reg: Date of problem: Mileage:
PROBLEM SYMPTOMS
Engine does not start
Vehicle does not move
(forward, rearward)
No lock-up (TCC clutch operation)
Shift point too high or too low
Excessive gear change shockEngine stops
Transmission does not shift
(1st, 2nd, 3rd, 4th, Rev) gear
Automatic shift does not occur
Transmission slipping in
(1st, 2nd, 3rd, 4th, Rev) gear
Other:
VEHICLE/ ENVIRONMENTAL CONDITION WHEN PROBLEM OCCURS
Environmental Condition
Weather
Temperature
Frequency
RoadFair/Cloudy/Rain/Snow/Always/Other ( )
Hot/Warm/Cool/Cold/(CF)/Always
Always/Sometimes/( times/ day, month)/Only Once
Urban/Suburb/Highway/Mountainous (uphill/downhill)/Paved road/Gravel/
Other( )
Vehicle Condition
Engine
Brake
O/D cut switch
P/N change switch
(P,R,N,D,2,L) range/( ) range
Cold/Warming up phase/Warmed up
At stop/During driving (constant speed/accelerating/decelerating/
right hand corner/left hand corner)/Other ( )/Speed ( km/h mile/h)
Speed( r/min)/Throttle opening(idle/about %/full)
Apply/Not apply
ON/OFF
Power/Normal
Malfunction indicator lamp condition
Always ON Sometimes ON Always OFF Good condition
Diagnostic trouble
codeFirst check : No codeMalfunction code( )
Second check : No code Malfunction code( )
Transmission range
Transmission temp.
Vehicle
CUSTOMER PROBLEM INSPECTION FORM (EXAMPLE)
NOTE:
The above form is a standard sample. It should be modified according to conditions characteristic of each
market.
YH4
GRAND
VITARA
1. Fluid pressure check hole
2. Oil pan
1. Oil pan
2. Exhaust pipe
7B1-54 AUTOMATIC TRANSMISSION (4 A / T)
LINE PRESSURE TEST
Purpose of this test is to check operating conditions of each part by
measuring fluid pressure in fluid pressure line. Line pressure test
requires following conditions.
Automatic fluid is at normal operating temperature (70 to 80C /
158 ± 176F).
Fluid is filled to proper level (between FULL HOT and LOW HOT
on dipstick).
1) Apply parking brake securely and place checks against wheels.
2) Attach oil pressure gauge to fluid pressure check hole in trans-
mission case.
Special Tool
(A): 09925-37810
CAUTION:
After attaching oil pressure gauge, check that not fluid
leakage exists.
3) Depress foot brake fully, run engine at idle and stall and then
check fluid pressure in ªDº or ªRº range.
CAUTION:
Do not continue running engine at stall speed longer than
5 seconds.
G16 Engine
Engine runningLine pressuregg
modeªDº rangeªRº range
At idle speed3.9 ± 4.4 kg / cm2
55 ± 63 psi
5.1 ± 5.7 kg / cm2
73 ± 81 psi
At stall speed11.7 ± 13.2 kg / cm2
166 ± 188 psi
14.2 ± 16.7 kg / cm2
202 ± 237 psi
J20 Engine
Engine runningLine pressuregg
modeªDº rangeªRº range
At idle speed3.8 ± 4.3 kg / cm2
54 ± 61 psi
5.3 ± 5.9 kg / cm2
75 ± 84 psi
At stall speed9.7 ± 11.2 kg / cm2
138 ± 159 psi
12.9 ± 15.5 kg / cm2
183 ± 220 psi
H25 Engine
Engine runningLine pressuregg
modeªDº rangeªRº range
At idle speed3.9 ± 4.4 kg / cm2
55 ± 63 psi
6.6 ± 7.2 kg / cm2
94 ± 102 psi
At stall speed11.3 ± 12.7 kg / cm2
161 ± 181 psi
14.7 ± 22.7 kg / cm2
209 ± 323 psi
YH4
GRAND
VITARA
1. 4WD switch
2. Transfer
3. Blank
4. Blank
5. ECM or PCM
6. Glove box7. Air pump assembly
8. Actuator
9. Axle lock clutch
10. Free axle hub
11. 4WD indicator lamp
7E-2 DIFFERENTIAL (FRONT)
4WD CONTROL SYSTEM
When the 4WD switch is turned ON by shifting the transfer shift lever, ECM (PCM) (G16 and J20 engine models)
or 4WD controller (H25 engine model) actuates (energizes) the air pump assembly. Then positive pressure is sent
from the air pump assembly to the actuator installed to the differential case and causes the axle lock clutch and
the free axle hub in the differential case to be engaged, resulting in the 4WD mode. Only when running in the 4WD
mode, front axles are joined to differential case, and they become free when 2WD mode is used (or when transfer
shift lever is shifted to N position), thereby reducing the power loss.
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.
YH4
GRAND
VITARA
DIFFERENTIAL (FRONT) 7E-7
1
1. ECM (PCM); viewed from harness side
4WD CONTROL CIRCUIT INSPECTION
Voltage Check [G16 and J20 engine models]
Check for input or output voltage (voltage between each circuit and
body ground) of ECM (PCM) with ECM (PCM) connector con-
nected and ignition switch turned ON.
TER-
MINALCIRCUITWIRE
COLORNORMAL
VOLTAGECONDITION
E6110 ± 14 VTransfer shift lever: 2H or NE61-
194WD Indicator lampOr / B0 ± 1 V4 seconds after transfer shift lever shifted
to 4H or 4L
C51 2Air pump assembly0 ± 1 VTransfer shift lever: 2H or NC51-2
-7(Pump motor and release
valve)R10 ± 14 V1 seconds after transfer shift lever shifted
to 4H or 4L
C51-24WD switchB/Or10 ± 14 VTransfer shift lever: 2H or N
-184WD switchB/Or0 ± 1 VTransfer shift lever: 4H or 4L
C51-
3-17GroundB/Bl0 ± 1 V±
C51 2Airpumpassembly0 ± 1 VTransfer shift lever: 2H or NC51-2
-27
Air um assembly
(pressure switch)P10 ± 14 V4 seconds after transfer shift lever shifted
to 4H or 4L
YH4
GRAND
VITARA
7E-8 DIFFERENTIAL (FRONT)
1. ECM (PCM); viewed from harness side
Voltage Check [H25 engine model]
TER-
MINALCIRCUITWIRE
COLORNORMAL
VOLTAGECONDITION
C51 110 ± 14 VTransfer shift lever: 2H or NC51-1
-74WD Indicator lampOr / B0 ± 1 V4 seconds after transfer shift lever shifted
to 4H or 4L
C51 1Air pump assembly0 ± 1 VTransfer shift lever: 2H or NC51-1
-15(Pump motor and release
valve)R10 ± 14 V1 seconds after transfer shift lever shifted
to 4H or 4L
C51-14WD switchB/Or10 ± 14 VTransfer shift lever: 2H or N
-114WD switchB/Or0 ± 1 VTransfer shift lever: 4H or 4L
C51-3
-26GroundB/Bl0 ± 1 V±
C51-1Airpumpassembly0 ± 1 VTransfer shift lever: 2H or NC51-1
-18
Air um assembly
(pressure switch)P10 ± 14 V4 seconds after transfer shift lever shifted
to 4H or 4L
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