Suzuki Grand Vitara JB416 / JB420. Manual - part 75

1A-249 Engine General Information and Diagnosis: 

9

A/C refrigerant pressure sensor voltage check
1) Check A/C refrigerant pressure sensor voltage referring 

to “Inspection of ECM and Its Circuits”.

Is voltage within specified value?

Go to Step 10.

Check amount of 
refrigerant. If OK, 
replace A/C refrigerant 
pressure sensor.

10 Radiator cooling fan check

1) Check radiator cooling fan referring to “Radiator Cooling 

Fan Motor On-Vehicle Inspection in Section 1F”.

Is check result satisfactory?

Radiator cooling fan 
drive circuit malfunction. 
If circuit is OK, go to 
Step 7.

Replace radiator cooling 
fan motor.

11 A/C compressor control system check

Is A/C compressor started when A/C and blower speed 
selector switch are turned ON with engine running?

A/C system is in good 
condition.

Go to Step 12.

12 A/C compressor relay circuit check

1) Measure voltage between “E23-49” wire terminal of 

ECM connector and vehicle body ground under following 
conditions respectively.

Voltage between “E23-49” terminal of ECM 
connector and ground
While engine running and A/C switch turned OFF: 10 
– 14 V
While engine running, A/C and blower speed 
selector switch turned ON: 0 – 1 V

Is check result satisfactory?

Go to Step 13.

Go to Step 14.

13 A/C compressor relay check

1) Check A/C compressor relay referring to “A/C 

Compressor Relay Inspection in Section 7B”.

Is it in good condition?

A/C compressor drive 
circuit malfunction.

Replace A/C 
compressor relay.

14 A/C compressor relay circuit check

1) Remove A/C compressor relay with ignition switch 

turned OFF.

2) Turn ON ignition switch, measure voltage between “YEL/

GRN” wire terminal of A/C compressor relay connector 
and vehicle body ground.

Is voltage 10 –14 V?

Go to Step 15.

“YEL/GRN” wire is open 
circuit.

15 A/C compressor relay check

1) Check A/C compressor relay referring to “A/C 

Compressor Relay Inspection in Section 7B”.

Is it in good condition?

“PNK” wire is open 
circuit. If OK, substitute 
a known-good ECM and 
recheck.

Replace A/C 
compressor relay.

Step

Action

Yes

No

Engine General Information and Diagnosis:  1A-250

Electric Load Signal Circuit Check

S5JB0A1104070

Wiring Diagram

WHT/BLU

BLU/ORN

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

G31-3

G31-1

2

C37-7

3

5

12V

4

I5JB0A110104-02

1. ECM

3. ABS hydraulic unit / control module 

assembly

5. Electric load signal (blower motor 

signal, rear defogger signal, headlight 
signal and A/C switch signal), etc.

2. BCM

4. PSP switch

1A-251 Engine General Information and Diagnosis: 

Troubleshooting

NOTE

• Before performed troubleshooting, be sure to read the “Precautions of ECM Circuit Inspection”.
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the 

special tool to ECM and/or the ECM connectors referring to “Inspection of ECM and Its Circuits”.

 

Step

Action

Yes

No

1

DTC check
1) Connect scan tool to DLC with ignition switch turned 

OFF.

2) Turn ON ignition switch and check DTC.

Is there DTC P1674 and/or P1678?

Go to applicable DTC 
diag. flow.

Go to Step 2.

2

Electric load signal circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Check electric load signal under following conditions 

respectively.

A/C switch signal
Engine running, A/C switch OFF: OFF
Engine running, A/C switch ON and blower speed 
selector turned 1st position or more: ON

Blower fan signal
Engine running, blower speed selector OFF: OFF
Engine running, blower speed selector 5th position 
or more: ON

PSP signal
Engine running, steering wheel to neutral position: 
OFF
Engine running, turning steering wheel to the right 
or left as far as it stops: ON

Electric load signal
Engine running, rear defogger switch or headlight 
switch OFF: OFF
Engine running, rear defogger switch or headlight 
switch ON: ON

Is check result satisfactory?

Electric load signal 
circuit is in good 
condition

Check defective signal 
circuit.

Engine General Information and Diagnosis:  1A-252

Radiator Cooling Fan Low Speed Control System Check

S5JB0A1104071

Wiring Diagram

Troubleshooting

WARNING

!

 

Keep hands, tools, and clothing away from engine cooling fan to help prevent personal injury. This fan 
is electric and can come on whether or not the engine is running. The fan can start automatically in 
response to the ECT sensor with the ignition switch at the “ON” position.

 

NOTE

• Before performed troubleshooting, be sure to read the “Precautions of ECM Circuit Inspection”.
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the 

special tool to ECM and/or the ECM connectors referring to “Inspection of ECM and Its Circuits”.

 

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

5V

RED/BLK

E23-46  

E23-47  

BLU/RED

BLU/YEL

BLU/BLK

E23-48  

PPL/YEL

GRY/GRN

C37-24  

C37-57  

1

BLK

RED

YEL/GRN

C37-15  

C37-29  
C37-48  

BLK/ORN

C37-58  

C37-30  BLK/ORN

BLK/YEL
BLK/YEL
BLK/YEL

RED/YEL

BLK

BLU

BLU

YEL/GRN

BLU/WHT

YEL/GRN

8

4

5

9

2

10

3

6

7

I5JB0A110105-01

1. Fuse box No.1

5. Radiator cooling fan relay No. 3

9. ECT sensor

2. Ignition switch

6. Radiator cooling fan motor No.1

10. “IG2 SIG” fuse

3. Radiator cooling fan relay No. 1

7. Radiator cooling fan motor No.2

4. Radiator cooling fan relay No. 2

8. ECM