Suzuki Grand Vitara JB416 / JB420 (ESP model). Service manual — part 36

3C-39 Transfer: Motor-Shift Type (Transfer with Shift Actuator)

DTC C1237: Center Differential Lock Switch Circuit Open

S5JB0E3314021

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: Motor-Shift Type (Transfer with
Shift Actuator)”.

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

Transfer: Motor-Shift Type (Transfer with Shift Actuator) 3C-40

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: Motor-
Shift Type (Transfer with
Shift Actuator)”.

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: Motor-Shift Type
(Transfer with Shift Actuator)”.

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.

3C-41 Transfer: Motor-Shift Type (Transfer with Shift Actuator)

DTC C1238: Center Differential Lock Switch Circuit Short

S5JB0E3314022

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: Motor-
Shift Type (Transfer with
Shift Actuator)”.

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.

Transfer: Motor-Shift Type (Transfer with Shift Actuator) 3C-42

DTC C1240: 4WD Control Module Power Supply Circuit Malfunction

S5JB0E3314023

Wiring Diagram

3

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

“Transfer Assembly Inspection: Motor-Shift Type
(Transfer with Shift Actuator)”.

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