Suzuki Grand Vitara JB416 / JB420 (ESP model). Service manual - part 18

1A-68 Engine General Information and Diagnosis: 

Reference waveform No.29
Oil control valve signal with engine racing (for M16 
engine)

Reference waveform No.30
CAN communication line signal with ignition switch 
turned ON

Reference waveform No.31
Ignition coil signal and fuel injector signal with engine 
cranking

Measurement 
terminal

CH1: “C37-60” to “C37-59”

Oscilloscope 
setting

CH1: 5 V/DIV
TIME: 400 

µs/DIV

Measurement 
condition

• After warmed up to normal 

operating temperature

• Drive vehicle at 20 km/h (12 mph) 

and depress accelerator pedal 
fully

1. Accelerator pedal depressed fully
2. Accelerator pedal depressed partially
3. Oil control valve signal
4. ON signal
5. OFF signal

Measurement 
terminal

CH1: “E23-4” to “C37-58”
CH2: “E23-19” to “C37-58”

Oscilloscope 
setting

CH1: 1 V/DIV, CH2: 1 V/DIV
TIME: 40 

µs/DIV

Measurement 
condition

Ignition switch turned ON
(Signal pattern is depending on 
communication data)

1. CAN communication line signal (High)
2. CAN communication line signal (Low)

I4RS0B110075-01

I5JB0A110094-01

Measurement 
terminal

CH1: “C37-52” to “C37-58”
CH2: “C37-21” to “C37-58”
CH3: “C37-1” to “C37-58”
CH4: “C37-22” to “C37-58”

Oscilloscope 
setting

CH1: 5 V/DIV, CH2: 5 V/DIV
CH3: 50 V/DIV, CH4: 10 V/DIV
TIME: 200 ms/DIV

Measurement 
condition

• After warmed up to normal 

operating temperature

• Engine at cranking

[A]: For J20 engine
[B]: For M16 engine

1. Cylinder reference signal (CMP reference signal)
2. Ignition coil signal
3. No.1 fuel injector signal
4. Engine start signal

I5JB0A110095-01

Engine General Information and Diagnosis:  1A-69

Resistance Check

1) Remove ECM from its bracket referring to “Engine Control Module (ECM) Removal and Installation in Section 1C 

in related manual”.

CAUTION

!

 

Never touch terminals of ECM itself or connect voltmeter or ohmmeter (2).

 

2) Connect special tool to ECM connectors securely.

NOTE
Do not connect the other connector of special tool to ECM.

 

3) Check resistance between each pair of terminals of disconnected connectors (1) as listed in the following table.

CAUTION

!

 

• Be sure to connect ohmmeter probe from wire harness side of coupler.
• Be sure to turn OFF ignition switch for this check.
• Resistance in the following table represents that measured when parts temperature is 20 

°C (68 °F).

 

1

2

I4RS0A110086-02

Terminals

Circuit

Standard resistance

Condition

E23-60 to E23-29

Main relay

160 – 240 

Ω

Battery disconnected 
and ignition switch 
turned ON

E23-15 to E23-29

Fuel pump relay

160 – 240 

Ω

—

C37-16 to E23-1/16 No.3 fuel injector

10.8 – 18.2 

Ω

—

C37-17 to E23-1/16 No.4 fuel injector

C37-5 to E23-1/16 EGR valve (stepping motor No.1 coil)

20 – 31 

Ω

—

C37-13 to E23-1/16 EVAP canister purge valve

28 – 35 

Ω

—

C37-2 to E23-1/16 No.2 fuel injector

10.8 – 18.2 

Ω

—

C37-6 to E23-1/16 EGR valve (stepping motor No.2 coil)

20 – 31 

Ω

—

C37-3 to E23-1/16 EGR valve (stepping motor No.4 coil)
C37-4 to E23-1/16 EGR valve (stepping motor No.3 coil)
C37-1 to E23-1/16 No.1 fuel injector

10.8 – 18.2 

Ω

—

C37-33 to E23-1/16 Intake manifold tuning vacuum solenoid valve

33 – 45 

Ω

—

C37-60 to C37-59

Oil control valve (for M16 engine)

6 – 15 

Ω

—

E23-50 to E23-1/16 Throttle actuator control relay

160 – 240 

Ω

—

1A-70 Engine General Information and Diagnosis: 

A/C System Circuits Check

S5JB0E1104085

Wiring Diagram

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  

BLK

RED

YEL/GRN

RED/YEL

BLK

BLU

BLU

BLU/WHT

YEL/GRN

5V

WHT/BLU

WHT/RED

E23-4

E23-19

RED

WHT

WHT/BLU

WHT/RED

RED

WHT

5V

PNK/GRN

YEL/RED

WHT/BLK

BLK/RED

12V

PNK

*RED

GRY/RED

GRY/BLK

C37-14  
C37-12  

WHT/RED

E23-49  

YEL/GRN

YEL/GRN

5V

1

2

4

9

11

12

15

16

5

8

14

13

7

10

3

6

I5JB0A110103-02

1. BCM

6. “IG2 SIG” fuse

11. Radiator cooling fan relay No.2

16. ECT sensor

2. ABS / ESP

® control module

7. “CPRSR” fuse

12. Radiator cooling fan relay No.3

*: For M16 engine

3. HVAC control module

8. Compressor relay

13. Radiator cooling fan No.1

4. ECM

9. Compressor

14. Radiator cooling fan No.2

5. Evaporator temperature sensor

10. Radiator cooling fan relay No.1

15. A/C refrigerant pressure sensor

Engine General Information and Diagnosis:  1A-71

Troubleshooting

NOTE

• Before performed troubleshooting, be sure to read the “Precautions of ECM Circuit Inspection in 

related manual”.

• 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”.

• When A/C evaporator outlet air temp. is below 0 

°C (32 °F) (for J20 engine) or 1.3 °C (34.3 °F) (for M16 

engine), A/C remains OFF (“E23-49” terminal voltage becomes 10 – 14 V). This condition is not 
abnormal.

 

Step

Action

Yes

No

1

Reception data check from BCM
1) Connect scan tool to DLC with ignition switch turned 

OFF.

2) Turn ON ignition switch.
3) Check DTC for reception data from BCM.

Is there DTC P1678?

Go to applicable DTC 
diag. flow.

Go to Step 2.

2

DTC check of HVAC control module
1) Check HVAC control module for DTC.

Is there DTC(s)?

Go to applicable DTC 
diag. flow.

Go to Step 3.

3

A/C switch signal circuit check
1) Start engine and select “DATA LIST” mode on scan tool.
2) Check A/C switch 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

Is check result satisfactory?

Go to Step 4.

Check HVAC control 
module and its circuit.

4

DTC check of ECT sensor circuit
1) Check ECM for DTC of ECT sensor circuit.

Is there DTC P0116, DTC P0117 or DTC P0118?

Go to applicable DTC 
diag. flow.

Go to Step 5.

5

Radiator cooling fan control system check

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

Go to Step 11.

Go to Step 6.

6

Radiator cooling fan control circuit check
1) Check DTC with scan tool.

Is DTC P0480 displayed?

Go to “DTC P0480: Fan 
1 (Radiator Cooling 
Fan) Control Circuit in 
related manual”.

Go to Step 7.

7

Evaporator temperature sensor check
1) Check evaporator temperature sensor referring to “A/C 

Evaporator Temperature Sensor Inspection in Section 
7B in related manual”.

Is resistance within specification?

Go to Step 8.

Faulty evaporator 
temperature sensor.