1998 SUZUKI GRAND VITARA air pump

YH4
GRAND
VITARA
7E-6 DIFFERENTIAL (FRONT)
STEPACTIONYESNO
1Turn ON ignition switch (but engine at stop) and
check malfunction indicator lamp.
Does lamp light up?Go to step 2.A trouble has
occurred at some
place. Repair it
referring to
MALFUNCTION
INDICATOR LAMP
(ªCHECK ENGINEº
LAMP) CHECK in
DIAGNOSIS of
SECTION 6.
2Check 4WD switch circuit.
Turn ignition switch ON and check that voltage
between terminal C51-2-18 and terminal C51-3-17
(ground) for G16 / J20 (terminal C51-1-11 and terminal
C51-3-26 (ground) for H25) is as follows.

When transfer shift lever is in N or 2H: 10 ± 14 V

When transfer shift lever is in 4L or 4H: 0 ± 1 V
Is the check result satisfactory?Go to step 3.Check 4WD switch
(refer to SECTION
7A), ªB / Orº and ªBº
circuits of 4WD
switch.
If OK, substitute a
known-good ECM
(PCM) and recheck.
3Check power supply.
1) Turn ignition switch ON.
2) Check voltage between C51-2-7 and C51-3-17
(ground) for G16 / J20 (C51-1-15 and C51-3-26
(ground) for H25). The check results should be as
follows.

When transfer shift lever is in N or 2H: 0 ± 1 V

When transfer shift lever is in 4L or 4H: 10 ± 14 V
Is the check result satisfactory?Go to step 4.Check ªRº circuit. If
it is OK, substitute a
known-good ECM
(PCM) and recheck.
4Check air pump assembly circuit.
1) Check for proper connection to air pump
assembly at all terminals.
2) Turn ignition switch ON.
3) Check voltage between C51-2-27 and C51-3-17
(ground) for G16 / J20 (C51-1-18 and C51-3-26
(ground) for H25). The check result should be as
follows.

When transfer shift lever is in 2H or N: 0 ± 1 V

When transfer shift lever is in 4L or 4H
(more than 4 seconds after shifted to 4L or 4H):
10 ± 14 V
Is the check result satisfactory?Go to step 5.Check air pump
assembly referring
to ªON-VEHICLE
SERVICEº, and then
ªPº circuit.
If OK, substitute a
known-good ECM
(PCM) and recheck.
5Check 4WD indicator lamp circuit.
1) Turn ignition switch ON.
2) Check voltage between E61-19 and C51-3-17
(ground) for G16 / J20 (C51-1-7 and C51-3-26
(ground) for H25). The check result should be as
follows.

When transfer shift lever is in 2H or N: 10 ± 14 V

When transfer shift lever is in 4L or 4H: 0 ± 1 V
Is the check result satisfactory?4WD control system
is in good condition.Check ªOr / Bº circuit
(including indicator
lamp and
combination meter).
If OK, substitute a
known-good ECM
(PCM) and recheck.

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
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.

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.

YH4
GRAND
VITARA
7E-12 DIFFERENTIAL (FRONT)
1. Pump assembly
Air Pump Assembly
Removal / Installation
1) Disconnect air hoses and coupler from air pump assembly.
2) Remove pump assembly by removing bolts.
3) Reverse removal procedure for installation.
Tightening Torque
(a): 13 N
.m (1.3 kg-m, 9.5 lb-ft)
Inspection
1) Install special tool, voltmeter and battery to pump assembly as
shown in figure.
2) Tighten adjusting screw of special tool as far as it stops and
close its air check side opening by using fuel hose as blind plug.
Special Tool
(A): 09918-18110
3) Check that motor starts to run (a sound can be heard) when bat-
tery is connected and it stops when specified pressure is ob-
tained.
Check also for air leakage.
Specified pressure: 30.0 ± 45.0 kPa
(0.30 ± 0.45 kg / cm
2, 4.25 ± 6.40 psi)
4) Check that value indicated on voltmeter is within specification
shown below.
When motor is running: 0 ± 1 V
When motor has stopped running: 10 ± 14 V
CAUTION:
Do not run motor more than 10 seconds continuously to
prevent motor breakage.

YH4
GRAND
VITARA
DIFFERENTIAL (FRONT) 7E-17
09951-16080
Bearing installer09951-26010
Bush remover plate09918-18110
Air pressure regulator
09367-04002
3-way joint
UNIT REPAIR
Refer to the same section of UNIT REPAIR MANUAL mentioned in FOREWORD of this manual.
TIGHTENING TORQUE SPECIFICATIONS
FasteningportionTightening torqueFastening ortionN.mKg-mlb-ft
Differential oil filler / level plug232.317.0
Differential oil drain plug232.317.0
Differential mounting front bolts858.561.5
Differential mounting bracket bolts505.036.5
Front drive shaft flange bolts505.036.5
Propeller shaft flange bolts505.036.5
Pump assembly bolts131.39.5
REQUIRED SERVICE MATERIAL
MATERIALRECOMMENDED
SUZUKI PRODUCTUSE
SealantSUZUKI BOND NO. 1215
(99000-31110)Front differential drain plug
SPECIAL TOOLS

YH4
GRAND
VITARA
INSTRUMENTATION / DRIVER INFORMATION 8C-9
1. Exhaust pipe
FUEL METER / FUEL GAUGE UNIT
FUEL METER
INSPECTION
1) Remove rear bumper facing.
2) Detach grommet (3) from vehicle.
3) Disconnect coupler (2) of fuel pump and gauge.
4) Turning switch ON, and check that fuel meter indicates E.
5) Turn ignition switch OFF.
6) Ground Bl / W lead through a 3.4 W test bulb (4) as illustrated.
7) Turn ignition switch ON and check that bulb light up and pointer
(5) moves to F side.
8) If fuel meter shows no operation, repair or replace defective
parts.
FUEL SENDER GAUGE
INSPECTION
1) Remove fuel pump assembly (1) referring to FUEL PUMP RE-
MOVAL in Section 6C.
2) Check resistance between terminals (A) and (B) under each
float position.
Float Position
FuelResistance (
)56
model66
modelMeterResistance (
)
ªaº88.3 mm
(3.48 in.)51.7 mm
(2.04 in.)F6 ± 8
ªbº157.2 mm
(6.20 in.)139.6 mm
(5.50 in.)1/229.5 ± 35.5
ªcº254.9 mm
(10.0 in.)254.9 mm
(10.0 in.)E94 ± 96
If measured valve is out of specification, replace fuel sender gauge.