Suzuki Grand Vitara JB416 / JB420 (ESP model). Service manual - part 102

10B-10 Body Electrical Control System: 

DTC U1073 (No. 1073): Control Module Communication Bus Off

S5JB0EA204013

Wiring Diagram

2

Outside air temperature sensor circuit check
1) Disconnect connector from BCM and check for proper 

terminal connection to BCM connector.

2) If connections are OK, check outside air temperature 

sensor circuit for open, short and high resistance.

Is each circuit in good condition?

Substitute a known-
good BCM (included in 
junction block 
assembly) and recheck.

Repair circuit.

Step

Action

Yes

No

WHT

RED

WHT

RED

G44-18

G44-19

G44

[A]

[B]

[C]

[H]

[G]

1

2

3

4

5

6

7

8

9

10

11

14

15

16
36

34 33 32

30 29

24 23

37

18

19

20

G28-8

G28-10

WHT/BLU

WHT/BLU

WHT/RED

WHT/RED E23-4

E23-19

WHT

RED

E53-13

E53-42

E53-44

E53-46

WHT

RED

E92-17

E92-7

WHT

RED

E91-22
E91-23

WHT

RED

RED

G31-1
G31-3

G31-4

6

5

16 15 14 13 12 11

4 3

24 23

21

22

10 9

8

7

2

1

19

20

18 17

E92

2 1

E23

3

4

18

19

5

6

7

10

11

17

20

47 46

49

50

51

21

22

52

16

25

9

24

14

29

55

57

5453

59

60

58

26

27

28

15
30

56

48

32 31

34

35

36

37

40

42

3938

44

45

43

41

33

12

13

23

8

1

2

3

4

5

6

7

8

9

10

11

17

1615141312

2221201918

G28

[F]

G31

E91

1

2

3

4

7

8

9

10

11

14

15

16
36

34

35

24 23

21

22

28 27

25

26

37

39 38

40

18 17

13 12

19

20

1

2

3

10

11

12

16

17

18

15 14 13

19

20

21

25

26

5

6

[E]

[D]

E03

15
16
17
18
19
20
21
22
23
24
25

2
3
4
5
6
7
8
9

10
11
12

1

13

14

26

8 7 6 5 4 3 2 1

9

10

11

12

13

14

15

16

G31-2

WHT

1

2

3

4

9

5

6

7

8

11

WHT

RED

G45-9
G45-10

10

[L]

[K]

E03-12

E03-10

E03-6

E03-8

[J]

E53

16

1

15

2

3

4

5

6

7

8

9

10

11

12

13

14

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

[I]

G45

10 9

3 2 1

I5JB0DA20004-01

[A]: Keyless start control module connector (viewed from harness side)

1. BCM

[B]: ECM connector (viewed from harness side)

2. 4WD control module (if equipped)

Body Electrical Control System:  10B-11

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) Check DTC and pending DTC.

DTC Troubleshooting

[C]: TCM connector (viewed from harness side)

3. TCM (A/T model)

[D]: DLC (viewed from terminal side)

4. Keyless start control module (if equipped)

[E]: ABS control module connector (viewed from terminal side)

5. DLC

[F]: Combination meter connector (viewed from harness side)

6. ECM

[G]: 4WD control module connector (viewed from harness side)

7. ABS control module

[H]: BCM connector (viewed from harness side)

8. Combination meter

[I]: Steering angle sensor connector (viewed from harness side)

9. Junction connector

[J]: ESP

® control module connector (viewed from terminal side)

10. ESP

® control module

11. Steering angle sensor (if equipped)

DTC detecting condition

Trouble area

Transmission error that is inconsistent between transmission data 
and transmission monitor (CAN bus monitor) data is detected more 
than 7 times continuously.
(1 driving detection logic)

• CAN circuit
• Combination meter
• BCM
• 4WD control module (if equipped)
• ABS or ESP

® control module

• TCM (A/T model)
• Keyless start control module (if equipped)
• ECM
• Steering angle sensor (if equipped)

Step

Action

Yes

No

1

Control module connector check
1) Check connection of connectors of all control modules 

communicating by means of CAN and reconnect 
securely.

2) Recheck DTC and reconnect securely.

Is DTC U1073 detected?

Go to Step 2.

Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 00 
in related manual”.

2

CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules 

communicating by means of CAN.

3) Check CAN communication circuit between control 

modules for open, short and high resistance.

Is each CAN communication circuit in good condition?

Go to Step 3.

Repair circuit.

10B-12 Body Electrical Control System: 

DTC U1100 (No. 1100): Lost Communication with ECM

S5JB0EA204014

Wiring Diagram
Refer to “DTC U1073 (No. 1073): Control Module Communication Bus Off”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) Check DTC.

DTC Troubleshooting

3

DTC check of BCM
1) Turn ignition switch to OFF position.
2) Connect connectors of disconnected control modules 

communicating by means of CAN.

3) Disconnect connector from any one of control modules 

other than BCM.

4) Recheck DTC for BCM.

Is DTC U1073 detected?

Disconnect connectors 
of control modules other 
than the one whose 
connector is 
disconnected in Step 3) 
one by one and check 
that DTC U1073 is 
detected by BCM each 
time connector is 
disconnected. When 
DTC U1073 is not 
detected by BCM while 
checking in this way, go 
to description under 
“NO” below. If DTC 
U1073 is detected by 
BCM even when 
connectors of all control 
modules that use CAN 
communication with 
BCM are disconnected, 
substitute a known-
good BCM and recheck.

Check power and 
ground circuit of control 
module disconnect in 
Step 3). If circuit is OK, 
substitute a known-
good control module 
disconnected in Step 3) 
and recheck.

Step

Action

Yes

No

DTC detecting condition

Trouble area

BCM can not receive CAN data from ECM for 
longer than specified time continuously.

• CAN communication circuit
• BCM 
• ECM

Step

Action

Yes

No

1

DTC check of BCM

Is DTC U1100 (No. 1100) and DTC U1073 (No. 1073) 
detected together?

Go to “DTC U1073 (No. 
1073): Control Module 
Communication Bus 
Off”.

Go to Step 2.

2

DTC check of ECM
1) Check ECM for DTC.

Is DTC P1674 detected?

Go to “DTC P1674: 
CAN Communication 
(Bus Off Error) in 
Section 1A”.

Go to Step 3.

3

DTC check of ABS or ESP

® control module

1) Check DTC for ABS or ESP

® control module.

Is DTC U1073 detected?

Go to “DTC U1073: 
Control Module 
Communication Bus Off 
in Section 4E”.

Go to Step 4.

Body Electrical Control System:  10B-13

4

Control module connector check
1) Check connection of connectors of all control modules 

communicating by means of CAN.

2) Recheck BCM for DTC.

Is DTC U1100 (No. 1100) detected?

Go to Step 5.

Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 00 
in related manual”.

5

DTC check of ABS or ESP

® control module

1) Check DTC for ABS or ESP

® control module.

Is DTC U1100 detected?

Go to Step 6.

Go to Step 7.

6

CAN communication circuit check
1) Disconnect connectors from ECM and ABS or ESP

® 

control module.

2) Check CAN communication circuit between ECM and 

ABS or ESP

® control module for open, short and high 

resistance.

Is each CAN communication circuit in good condition?

Check ECM power and 
ground circuit. If circuit 
is OK, substitute a 
known-good ECM and 
recheck.

Repair circuit.

7

CAN communication circuit check
1) Disconnect connectors from BCM and ABS or ESP

® 

control module.

2) Check CAN communication circuit between BCM and 

ABS or ESP

® control module for open, short and high 

resistance.

Is each CAN communication circuit in good condition?

Go to Step 8.

Repair circuit.

8

CAN communication circuit check
1) Disconnect connectors of all control modules 

communicating by means of CAN.

2) Check CAN communication circuit between control 

modules other than Step 7 for open, short and high 
resistance.

Is each CAN communication circuit in good condition?

Go to Step 9.

Repair circuit.

9

DTC check of BCM
1) Connect connectors of disconnected control modules 

communicating by means of CAN.

2) Disconnect connector of any one of control module other 

than BCM.

3) Recheck BCM for DTC.

Is DTC U1100 (No.1100) detected?

Disconnect connectors 
of control modules other 
than the one whose 
connector is 
disconnected in Step 2) 
one by one and check 
that DTC U1100 is 
detected by BCM each 
time connector is 
disconnected. When 
DTC U1100 is not 
detected by BCM while 
checking in this way, go 
to description under 
“NO” below. If DTC 
U1100 is detected by 
BCM even when 
connectors of all control 
modules that use CAN 
communication with 
BCM are disconnected, 
substitute a known-
good BCM and recheck.

Check power and 
ground circuit of control 
module disconnected in 
Step 2). If circuit is OK, 
substitute a known-
good control module 
disconnected in Step 2) 
and recheck.

Step

Action

Yes

No