Suzuki Grand Vitara JB627. Manual - part 159

3C-40 Transfer: 

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Select transfer switch to “4H” position and keep its position for 1 min.
3) Check DTC.

Troubleshooting

DTC detecting condition

Trouble area

Though transfer shift actuator motor position switch is “4H” 
position, the ON signal is not input from the center differential 
lock switch.

• Center differential lock switch
• Center differential lock switch circuit
• 4WD control module

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

Center differential lock switch circuit check
1) Disconnect center differential lock switch connector with 

ignition switch OFF.

2) Check for proper connection to terminal of center 

differential lock switch connector.

3) If connection is OK, measure voltage between “RED/

GRN” terminal of center differential lock switch 
connector and vehicle body ground with ignition switch 
ON.

Is it 10 – 14 V?

Go to Step 3.

Go to Step 4.

3

Center differential lock switch check
1) Check center differential lock switch referring to 

“Transfer Assembly Inspection”.

Is switch in good condition?

Substitute a known-
good 4WD control 
module and recheck.

Replace center 
differential lock switch.

4

Wire harness check
1) Disconnect connector from 4WD control module 

connector “E91” with ignition switch OFF.

2) Check for proper connection to “E91-14” terminal of 

4WD control module connector.

3) If OK, measure resistance between “RED/GRN” terminal 

of center differential lock switch connector and “E91-14” 
terminal of 4WD control module connector.

Is it 1 

Ω

 or less?

Substitute a known-
good 4WD control 
module and recheck.

“RED/GRN” wire is 
open or high resistance.

Transfer: 3C-41

DTC C1238: Center Differential Lock Switch Circuit Short

S6JB0B3304022

Wiring Diagram

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Select transfer switch to “4L-lock” position and keep its position for 1 min.
3) Check DTC.

Troubleshooting

IG

E91-13

E91-14

RED/GRN

PNK/WHT

2

3

4

12V

1

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

[A]

I5JB0A332018-01

[A]: 4WD control module connector “E91” (viewed from harness side)

3. 4L/N switch

1. 4WD control module

4. Center differential lock switch

2. TCM

DTC detecting condition

Trouble area

Though transfer shift actuator motor position switch is “4L-lock” 
position, the OFF signal is not input from the center differential 
lock switch.

• Center differential lock switch
• Center differential lock switch circuit
• 4WD control module

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

Center differential lock switch circuit check
1) Disconnect center differential lock switch connector with 

ignition switch OFF.

2) Check for proper connection to terminal of center 

differential lock switch connector.

3) If connection is OK, measure voltage between “RED/

GRN” terminal of center differential lock switch 
connector and vehicle body ground with ignition switch 
ON.

Is it 10 – 14 V?

Go to Step 3.

Go to Step 4.

3C-42 Transfer: 

DTC C1240: 4WD Control Module Power Supply Circuit Malfunction

S6JB0B3304023

Wiring Diagram

3

Center differential lock switch check
1) Check center differential lock switch referring to 

“Transfer Assembly Inspection”.

Is switch in good condition?

Substitute a known-
good 4WD control 
module and recheck.

Replace center 
differential lock switch.

4

Wire harness check
1) Disconnect connector from 4WD control module 

connector “E91” with ignition switch OFF.

2) Check for proper connection to “E91-14” terminal of 

4WD control module connector.

3) If OK, measure resistance between “RED/GRN” terminal 

of center differential lock switch connector and “E91-14” 
terminal of 4WD control module connector.

Is it 1 M

Ω

 or more?

Substitute a known-
good 4WD control 
module and recheck.

“RED/GRN” wire is 
shorted to ground 
circuit.

Step

Action

Yes

No

5V

+BB

E91-12

E91-11

E91-10

E91-1

BLK

BLK

WHT

BLK/WHT

2

4

6

3

5

7 

1

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

[A]

BLK

I5JB0A332019-01

[A]: 4WD control module connector “E91” (viewed from harness side)

4. “4WD” fuse

1. 4WD control module

5. Shift switch (for A/T model) or CPP switch (for M/T model)

2. “IG COIL” fuse 

6. Main fuse box

3. Ignition switch

7. Starting motor

Transfer: 3C-43

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Start engine and drive vehicle at 30 km/h (19 mph) or more vehicle speed at least for 1 min.
3) Stop vehicle and check DTC.

Troubleshooting

DTC C1243: Internal Circuit Malfunction of 4WD Control Module

S6JB0B3304024

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Clear DTC using scan tool.
2) Turn ignition switch to ON position for 60 seconds.
3) Check DTC.

Troubleshooting
Substitute a known-good 4WD control module and recheck.

DTC detecting condition

Trouble area

4WD control module power supply voltage is out of specification 
while vehicle is running at 20 km/h (12 mph) or more.

• 4WD control module power supply circuit

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

4WD control module power circuit check
1) Disconnect 4WD control module connector with ignition 

switch OFF.

2) Check for proper connection to “E91” terminal of 4WD 

control module connector.

3) If connection is OK, measure voltage between “E91-11” 

terminal of 4WD control module connector and vehicle 
body ground with ignition switch ON.

Is it 10 – 14 V?

Poor “E91-11” 
connection or 
intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”. If wire and 
connections are OK, 
substitute a known-
good 4WD control 
module and recheck.

“4WD” fuse blown, 
“WHT” or “BLK” wire is 
circuit open or circuit 
short.

DTC detecting condition

Trouble area

EEPROM Error

• 4WD control module