2001 SUZUKI GRAND VITARA 4WD SWITCH

DIFFERENTIAL (FRONT) 7E-3
Diagnosis
Differential Assembly Diagnosis Table
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 “4WD CONTROL SYSTEM INSPECTION” in
this section for air leakage.
Notes on system circuit inspection
•Be sure to read “PRECAUTIONS FOR ELECTRICAL CIRCUIT SERVICE” in Section 0A before circuit
inspection and observe what is written there.
•For system circuit, refer to the figure of “GENERAL DESCRIPTION” in this section.
•For terminal arrangement, refer to “4WD CONTROL CIRCUIT INSPECTION” in this section. Condition Possible Cause Correction
Gear noiseDeteriorated or water mixed lubricant Repair and replenish.
Inadequate or insufficient lubricant Repair and replenish.
Maladjusted backlash between bevel pinion and gear Adjust.
Improper tooth contact in the mesh between bevel pinion
and gearAdjust or replace.
Loose bevel gear securing bolts Replace or retighten.
Damaged side gear(s) or side pinion(s) Replace.
Bearing noise(Constant noise) Deteriorated or water mixed lubricant Repair and replenish.
(Constant noise) Inadequate or insufficientlubricant Repair and replenish.
(Noise while coasting) Damaged bearing(s) of bevel pinion Replace.
(Noise while turning) Damaged differential side bearing(s)
or axle bearing(s)Replace.
Oil leakageWorn or damaged oil seal Replace.
Excessive oil Adjust oil level.
Loose differential carrier bolts Replace or retighten.
2WD/4WD
switching errorDefective actuator Replace.
Abnormality in 4WD control system Inspect referring to “4WD
CONTROL SYSTEM DIAG-
NOSTIC FLOW TABLE”.

7E-4 DIFFERENTIAL (FRONT)
Flow table
Step Action Yes No
1 Turn 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 INDI-
CATOR LAMP
(“CHECK ENGINE”
LAMP) CHECK in
DIAGNOSIS of Sec-
tion 6.
2 Check 4WD switch circuit.
Turn ignition switch ON and check that voltage
between terminal C51-3-7 and terminal C51-3-17
(ground) 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),
“BLK/ORN” and “BLK”
circuits of 4WD switch.
If OK, substitute a
known-good ECM
(PCM) and recheck.
3 Check power supply.
1) Turn ignition switch ON.
2) Check voltage between C51-1-9 and C51-3-17
(ground). 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 “RED” circuit. If
it is OK, substitute a
known-good ECM
(PCM) and recheck.
4 Check air pump assembly circuit.
1) Check for proper connection to air pump assem-
bly at all terminals.
2) Turn ignition switch ON.
3) Check voltage between C51-3-18 and C51-3-17
(ground). 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
“ON-VEHICLE SER-
VICE”, and then
“PNK” circuit.
If OK, substitute a
known-good ECM
(PCM) and recheck.
5 Check 4WD indicator lamp circuit.
1) Turn ignition switch ON.
2) Check voltage between E61-19 and C51-3-17
(ground). 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 “ORN/BLK” cir-
cuit (including indica-
tor lamp and
combination meter).
If OK, substitute a
known-good ECM
(PCM) and recheck.

DIFFERENTIAL (FRONT) 7E-5
4WD Control System Circuit Inspection
Voltage check
Check for input or output voltage (voltage between each circuit and body ground) of ECM (PCM) with ECM
(PCM) connector connected and ignition switch turned ON.
TER-
MINALCIRCUITWIRE
COLORNORMAL
VOLTAGECONDITION
E61-19 4WD Indicator lampORN/
BLK10 –14 V Transfer shift lever : 2H or N
0 – 1 V4 seconds after transfer shift lever shifted
to 4H or 4L
C51-1-9Air pump assembly
(Pump motor and release
valve)RED 0 – 1 V Transfer shift lever : 2H or N
10 – 14 V1 seconds after transfer shift lever shifted
to 4H or 4L
C51-3-7 4WD switchBLK/
ORN10 – 14 V Transfer shift lever : 2H or N
0 – 1 V Transfer shift lever : 4H or 4L
C51-3-17 GroundBLK/
ORN 0 – 1 V –
C51-3-18Air pump assembly
(pressure switch)PNK 0 – 1 V Transfer shift lever : 2H or N
10 – 14 V4 seconds after transfer shift lever shifted
to 4H or 4L
1. ECM (PCM) connector terminal arrangement ; viewed from harness side

7E-6 DIFFERENTIAL (FRONT)
4WD Control System Inspection
1) Install special tool to air hose connecting between air pump
assembly and differential (actuator) as shown in figure.
Tighten adjusting screw (2) of special tool as far as it stops.
Close air check side opening by using fuel hose (1) as blind
plug.
Special tool
(A) : 09918-18110
SUZUKI GENUINE PARTS
(B) : 09367-04002
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 indi-
cates specified pressure value.
Check also for air leakage.
Air pressure specification
(for 4WD control system inspection) :
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.
Loosen adjusting screw (2) to lower pressure value on
gauge. Motor should start to run again and stop in about 4
seconds.
6) With the adjusting screw (2) 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. NOTE:
Use care not to bend any part of hose.
3. pipe (to air pump assembly)
4. Hose (to differential carrier)
5. Differential housing

INSTRUMENTATION/DRIVER INFORMATION 8C-3
COMBINATION METER INTERNAL CIRCUITS
COMBINATION METER COUPLERS
[A] : Coupler A [B] : Coupler B [C] : Coupler C
1. To Cruise control module (if equipped) GRY/YEL 1. To door switch (drive side) BLK/BLU 1. To ground BLK
2. Blank–2. To transmission range switch
(A/T vehicle only, if equipped) LGRN/BLU 2. To ECM (PCM for A/T vehicle) BRN
3. To ignition switch BLK/WHT 3. To transmission range switch
(A/T vehicle only, if equipped) 2GRN/ORN 3. To ignition switch PPL/RED
4. Blank–4. To transmission range switch
(A/T vehicle only, if equipped) DYEL/GRN 4. To brake fluid level switch RED/BLK
5. To ABS control module (if equipped) BLU/ORN 5. To transmission range switch
(A/T vehicle only, if equipped) NORN/BLU 5. To parking brake switch PPL
6. To PCM (A/T vehicle only) GRY/BLU 6. To transmission range switch
(A/T vehicle only, if equipped) PORN/GRN 6. To seat belt switch GRY/RED
7. To ABS control module (if equipped) BRN 7. To transmission range switch
(A/T vehicle only, if equipped) RRED 7. To generator WHT/RED
8. To VSS BLU/YEL 8. To illumination control module RED/GRN 8. To engine oil pressure switch YEL/BLK
9. To combination switch GRN/RED 9. To PCM (A/T vehicle only) WHT/BLK 9. To combination switch RED/YEL
10. To air bag SDM BLU 10. To ECT sensor YEL/WHT 10. To ignition switch BLU/RED
11. To main fuse WHT/BLU 11. To fuel level gauge BLU/WHT
12. To fuse box WHT 12. To ground BLU/YEL
13. To combination switch RED 13. To combination switch GRN/YEL
14. To immobilizer control module
(if equipped)PPL
15. To ECM (PCM for A/T vehicle) PPL/YEL
16. To ECM (PCM for A/T vehicle) ORN/BLK
P R N D 2 LCRUISEPOWER4WDSPEED
METERTACHO
METERFUEL
METERTEMP.
METER
A-11
A-13 A-8 B-12 B-11 C-8 A-15 A-6 A-1 B-9 A-16 A-14 C-7 C-1 A-10 C-3 C-4 C-5 A-7 A-5 B-8 B-1B-10 C-2 A-12 A-3B-13 B-2 B-3 B-4 B-5 B- B-6 C-9 C-10 A-9ABS circuit EBD circuit Air bag circuit
or ABS or BRAKE
if equipped
or CHECK
ENGINE
NOTE:
Terminal arrangement of coupler viewed from harness side.