Page 508 of 801

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.
Page 536 of 801

YH4
GRAND
VITARA
LIGHTING SYSTEM 8B-5
CLEARANCE, TAIL AND LICENCE PLATE LIGHTS
TroublePossible causeCorrection
All lights do not lightªTAILº fuse blown
Lighting switch faulty
Wiring or grounding faultyReplace fuse to check for short
Replace switch
Repair
Some lights do not light
upBulb(s) blown
Wiring or grounding faultyReplace bulb(s)
Repair
BACK-UP LIGHTS
TroublePossible causeCorrection
Back-up lights do not
lightªTURN / BACKº fuse blown (Hard Top Model)
ªTRNº fuse blown (Canvas Top Model)
Bulb blown
switch faulty
Wiring or grounding faultyReplace fuse to check for short
Replace bulb
Replace switch
Repair
Back-up lights remains
ONBack-up light switch or shift switch faulty
Wiring or grounding faultyReplace switch
Repair
BRAKE LIGHTS
TroublePossible causeCorrection
Brake lights do not light
upªSTOP / HORNº fuse blown (Hard Top
Model)
ªSTPº fuse blown (Canvas Top Model)
Bulb(s) blown
Brake light switch faulty
Wiring or grounding faultyReplace fuse to check for short
Replace bulb(s)
Adjust or replace switch
Repair
Brake lights stay onBrake light switch faultyAdjust or replace switch
Only one light does not
lightBulb blown
Wiring or grounding faultyReplace bulb
Repair
REAR FOG LIGHT (IF EQUIPPED)
TroublePossible causeCorrection
Rear fog light does not
come onªFOGº fuse blown
Rear fog light switch faulty
Lighting switch faulty
Wiring or grounding faulty
Bulb blownReplace fuse to check for short
Replace fog light switch
Replace switch
Repair
Replace bulb
INTERIOR LIGHTS
TroublePossible causeCorrection
Interior light (s) does (do)
not light upBulb(s) blown
ªDOMEº fuse blown (Hard Top Model)
ªDOMº fuse blown (Canvas Top Model)
Wiring or grounding faulty
Door switch faulty
Interior light switch faultyReplace bulb(s)
Replace fuse to check for short
Repair
Replace switch
Replace light assy
Front spot lights do not
light upBulb(s) blown
Wiring or grounding faulty
Spot light switch faultyReplace bulb(s)
Repair
Replace light assy
Page 553 of 801
YH4
GRAND
VITARA
G16
J20
H25
1. Oil pressure switch
INSTRUMENTATION / DRIVER INFORMATION 8C-11
INSPECTION
1) Warm up ECT sensor (1) observing resistance between sensor
terminal (2) and sensor unit (1). Resistance should be de-
creased with increase of its temperature.
2) Check resistance between sensor terminal (2) and sensor unit
(1) shown below. If check result is not as specified, replace sen-
sor.
Temperature
Resistance
50C (122F)136 ± 216
OIL PRESSURE LIGHT
OIL PRESSURE SWITCH
REMOVAL AND INSTALLATION
Refer to OIL PRESSURE CHECK in Section 6A1 (for G16), Section
6A2 (for H25), and Section 6A4 (for J20) of this manual for details.
INSPECTION
1) Disconnect oil pressure switch (1) lead wire.
2) Check for continuity between oil pressure switch terminal (2)
and cylinder block (3) as shown.
During Engine Running
No continuity
At Engine StopContinuity
If check result is not as specified, replace oil pressure switch (1).