Suzuki Grand Vitara JB627. Manual - part 158

3C-36 Transfer: 

DTC C1228: 4L/N Switch Circuit Short

S6JB0B3304019

Wiring Diagram

DTC Detecting Condition and Trouble Area

4

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

connector “E91” with ignition switch OFF.

2) Check for proper connection to “E91-13” terminal of 

4WD control module connector.

3) If OK, measure resistance between “PNK/WHT” terminal 

of 4L/N switch connector and “E91-13” terminal of 4WD 
control module connector.

Is it 1 

Ω

 or less?

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

“PNK/WHT” wire is 
open or high resistance.

Step

Action

Yes

No

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 4L/N switch.

• 4L/N switch
• 4L/N switch circuit
• 4WD control module

Transfer: 3C-37

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

Step

Action

Yes

No

1

Was “4WD control system check” performed?

Go to Step 2.

Go to “4WD Control 
System Check”.

2

4L/N switch circuit check
1) Disconnect 4L/N switch connector with ignition switch 

OFF.

2) Check for proper connection to terminal of 4L/N switch 

connector.

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

WHT” terminal of 4L/N switch connector and vehicle 
body ground with ignition switch ON.

Is it 10 – 14 V?

Go to Step 3.

Go to Step 4.

3

4L/N switch check
1) Check 4L/N switch referring to “Transfer Assembly 

Inspection”.

Is switch in good condition?

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

Replace 4L/N switch.

4

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

connector “E91” with ignition switch OFF.

2) Check for proper connection to “E91-13” terminal of 

4WD control module connector.

3) If OK, measure resistance between “PNK/WHT” terminal 

of 4L/N switch connector and “E91-13” terminal of 4WD 
control module connector.

Is it 1 M

Ω

 or more?

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

“PNK/WHT” wire is 
shorted to ground 
circuit.

3C-38 Transfer: 

DTC C1230: Transfer Actuator Circuit Malfunction

S6JB0B3304020

Wiring Diagram

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 10 seconds. Similarly select transfer switch to “4H-

lock”, “N” and “4L-lock” position.

3) Check DTC.

Troubleshooting

5V

12V

E91-2

5V

YEL

RED/BLK

BLU

M

E91-3

E91-25

E91-26

RED

E91-24

BLK/YEL

1

2

3

C54-1

C54-4

C54-2

C54-3

C54-5

4

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]

1

2

3

4

5

6

[B]

I5JB0A332017-01

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

2. Transfer shift actuator motor position switch

[B]: Transfer shift actuator connector “C54” (engine harness side) (viewed from harness side)

3.  Transfer shift actuator motor

1. Transfer shift actuator

4. 4WD control module

DTC detecting condition

Trouble area

• Position switch in transfer shift actuator is not changed for 3 

seconds even if command signal of motor relay for transfer 
shift actuator (included in 4WD control module) is turned on.

or
• Monitor signal from motor relay of transfer shift actuator 

(included in 4WD control module) is inconsistent with 
command signal to motor relay of transfer shift actuator.

• Transfer shift actuator
• Transfer shift actuator 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”.

Transfer: 3C-39

DTC C1237: Center Differential Lock Switch Circuit Open

S6JB0B3304021

Wiring Diagram

2

Transfer shift actuator circuit check
1) Disconnect transfer shift actuator connector “C54” with 

ignition switch OFF.

2) Check for proper connection to “C54-1” and “C54-4” 

terminals of transfer shift actuator connector.

3) If connection is OK, measure voltage between “C54-1” 

or “C54-4” terminal of transfer shift actuator connector 
and vehicle body ground.

Is it 10 – 14 V?

Go to Step 3.

Go to Step 4.

3

Transfer shift actuator check
1) Check transfer shift actuator referring to “Transfer 

Assembly Inspection”.

Is actuator in good condition?

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

Replace transfer shift 
actuator.

4

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

connector “E91” with ignition switch OFF.

2) Check for open and high resistance or shorted to ground 

in related circuits.
• Between “C54-1” terminal of transfer shift actuator 

connector and “E91-22” terminal of 4WD control 
module connector

• Between “C54-4” terminal of transfer shift actuator 

connector and “E91-3” terminal of 4WD control 
module connector

Are they in good condition?

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

Repair circuit.

Step

Action

Yes

No

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