Suzuki Grand Vitara JB416 / JB420. Manual - part 55

1A-169 Engine General Information and Diagnosis: 

DTC Troubleshooting

NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to 
“Precautions For DTC Troubleshooting”.

 

Step

Action

Yes

No

1

Was “Engine and Emission Control System Check” 
performed?

Go to Step 2.

Go to “Engine and 
Emission Control 
System Check”.

2

Electric load current sensor power/ ground circuit 
check
1) Disconnect connector from electric load current sensor 

with ignition switch turned OFF.

2) Check for proper connection of wire terminal to electric 

load current sensor connector.

3) If connections are OK, check electric load current sensor 

circuit for the following.
• Resistance between ground circuit wire of electric 

load current sensor connector and vehicle body 
ground is less than 1 

Ω (ground circuit check)

• Voltage between 5 V power circuit wire of electric load 

current sensor connector and vehicle body ground is 
4 – 6 V with ignition switch tuned ON (power circuit 
check)

Is it in good condition?

Go to Step 3.

Repair or replace 
defective wire and/or 
check connected 
sensors to this circuit.

3

Electric load current sensor output circuit check
1) Disconnect connector from ECM with ignition switch 

turned OFF.

2) Check for proper connection of electric load current 

sensor wire terminal to ECM connector.

3) If connections are OK, check electric load current sensor 

circuit for the following.
• Resistance of electric load current sensor output 

circuit wire between electric load current sensor 
connector and ECM connector is less than 1 

Ω 

(continuity check)

• Resistance between electric load current sensor 

output circuit wire of electric load current sensor 
connector and vehicle body ground is infinity 
(insulation check)

• Voltage between electric load current sensor output 

circuit wire of electric load current sensor connector 
and vehicle body ground is 0 V with ignition switch 
tuned ON (power circuit short check)

Is it in good condition?

Go to Step 4.

Repair or replace 
defective wire.

4

Electric load current sensor check
1) Check for electric load current sensor output referring to 

“Electric Load Current Sensor On-Vehicle Inspection 
(For J20 Engine) in Section 1C”.

Is check result satisfactory?

Substitute a known 
good ECM and recheck.

Replace electric load 
current sensor.

Engine General Information and Diagnosis:  1A-170

DTC P1510: ECM Back-Up Power Supply Malfunction

S5JB0A1104056

Wiring Diagram

Circuit Description
Battery voltage is supplied so that DTC memory, values for engine control learned by ECM, etc. are kept in ECM even 
when the ignition switch is turned 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 using scan tool and run engine at idle speed for 1 min.
3) Check DTC and pending DTC.

E23

C37

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

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

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

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

2

1

E23-2  

WHT

WHT

I5JB0A110066-01

1. ECM
2. “DOME” fuse

DTC detecting condition

Trouble area

Back-up power circuit voltage is no inputted for 5 seconds 
continuously while engine is running.
(1 driving cycle detection logic)

Battery voltage supply circuit

1A-171 Engine General Information and Diagnosis: 

DTC Troubleshooting

NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to 
“Precautions For DTC Troubleshooting”.

 

Step

Action

Yes

No

1

Was “Engine and Emission Control System Check” 
performed?

Go to Step 2.

Go to “Engine and 
Emission Control 
System Check”.

2

Battery voltage supply circuit check
1) Turn OFF ignition switch.
2) Remove ECM from its bracket with ECM connectors 

connected.

3) With engine running, measure voltage between “E23-2” 

terminal of ECM connector and engine ground.

Is voltage 10 – 14 V?

Poor “E23-2” 
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 ECM and 
recheck.

“DOME” fuse blown, 
“WHT” wire is circuit 
open or short circuit.

Engine General Information and Diagnosis:  1A-172

DTC P1603: TCM Trouble Code Detected (For J20 Engine)

S5JB0A1104057

Wiring Diagram

DTC Detecting Condition
When ECM receives a trouble code from TCM, which indicates that some problem occurred in sensor circuits and its 
calculated values used for operations such as idle speed control, engine power control, and so on by TCM, ECM sets 
DTC P1603. (TCM outputs the trouble code to ECM when TCM can not compute the engine control signal due to 
malfunctions of sensor circuits used for gear shift control.)

DTC Troubleshooting

NOTE
Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to 
“Precautions For DTC Troubleshooting”.

 

WHT/BLU

WHT/RED

E23

C37

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

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

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

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

E23-4

E23-19

1

RED

WHT

E03-12

E03-6

WHT/BLU

WHT/RED

E03-8

E03-10

RED

WHT

E92-7

E92-17

2

3

I5JB0A110067-02

1. ECM

2. TCM (for A/T model)

3. ABS hydraulic unit / control module assembly

Step

Action

Yes

No

1

Was “Engine and Emission Control System Check” 
performed?

Go to Step 2.

Go to “Engine and 
Emission Control 
System Check”.

2

DTC check
1) Check DTC of TCM referring to “DTC Check in Section 

5A”.

Is there any DTC(s)?

Go to applicable DTC 
diag. flow.

Substitute a known-
good ECM and recheck.