Suzuki Grand Vitara JB416 / JB420. Manual - part 35

1A-89 Engine General Information and Diagnosis: 

3

ECM voltage check
1) Disconnect connector from MAF and IAT sensor with 

ignition switch turned OFF.

2) Check for proper connection to MAF and IAT sensor at 

“LT GRN” and “GRY/GRN” wire terminals.

3) If OK, then turn ON ignition switch, measure voltage 

between “LT GRN” wire terminal of MAF and IAT sensor 
connector (1) and vehicle body ground.

Is voltage about 4 – 6 V?

Go to Step 6.

Go to Step 4.

4

IAT short circuit check
1) Disconnect connectors from ECM with ignition switch 

turned OFF.

2) Measure resistance between “LT GRN” wire terminal of 

MAF and IAT sensor connector and vehicle body 
ground.

Is resistance infinity?

Go to Step 5.

“LT GRN” wire is 
shorted to ground 
circuit.
If wire is OK, substitute 
a known-good ECM and 
recheck.

5

IAT short circuit check
1) Turn ON ignition switch.
2) Measure voltage between “LT GRN” wire terminal of 

MAF and IAT sensor connector and vehicle body 
ground.

Is voltage about 0 V?

Go to Step 6.

“LT GRN” wire is 
shorted to other circuit.
If wire is OK, substitute 
a known-good ECM and 
recheck.

6

IAT sensor for performance check
1) Check IAT sensor according to “Mass Air Flow (MAF) 

and Intake Air Temperature (IAT) Sensor Inspection in 
Section 1C”.

Is it in good condition?

Substitute a known-
good ECM and recheck.

Replace MAF and IAT 
sensor.

Step

Action

Yes

No

I5JB0A110037-02

Engine General Information and Diagnosis:  1A-90

DTC P0113: Intake Air Temperature Sensor Circuit High

S5JB0A1104025

Wiring Diagram
Refer to “DTC P0111: Intake Air Temperature Circuit Range / Performance”.

DTC Detecting Condition and Trouble Area

NOTE
When DTC P0108, P0118 and P0533 are indicated together, it is possible that “GRY/GRN” wire circuit is 
open.

 

DTC Confirmation Procedure

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC and pending DTC.

DTC Troubleshooting

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

 

DTC detecting condition

Trouble area

DTC will be set when all of following conditions are detected for 
0.5 seconds continuously.
• Engine is running
• Voltage of IAT sensor output is more than specified value

(Low intake air temperature (high voltage / high resistance))

(1 driving cycle detection logic)

• IAT sensor circuit
• IAT sensor
• ECM

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

IAT sensor and its circuit check
1) Connect scan tool to DLC with ignition switch turned 

OFF.

2) Turn ON ignition switch.
3) Check intake air temp. displayed on scan tool.

Is –40 

°

C (–40 

°

F) indicated?

Go to Step 3.

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

1A-91 Engine General Information and Diagnosis: 

3

IAT sensor voltage check
1) Disconnect connector from MAF and IAT sensor with 

ignition switch turned OFF.

2) Check for proper connection to MAF and IAT sensor at 

“LT GRN” and “GRY/GRN” wire terminals.

3) If OK, then turn ON ignition switch, measure voltage 

between “LT GRN” wire terminal of MAF and IAT sensor 
connector (1) and vehicle body ground.

Is voltage about 4 – 6 V?

Go to Step 7.

Go to Step 4.

4

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

connected.

3) Check for proper connection of ECM connector at “C37-

25” terminal.

4) If OK, then turn ON ignition switch, measure voltage 

between “C37-25” terminal of ECM connector and 
vehicle body ground.

Is voltage about 4 – 6 V?

“LT GRN” wire is open 
circuit. If wire and 
connection are OK, go 
to Step 5.

Go to Step 5.

5

Wire circuit check
1) Disconnect connectors from ECM with ignition switch 

turned OFF.

2) Turn ON ignition switch.
3) Measure voltage between “LT GRN” wire terminal of 

MAF and IAT sensor connector and vehicle body 
ground.

Is voltage about 0 V?

Go to Step 6.

“LT GRN” wire is 
shorted to other circuit.
If wire is OK, substitute 
a known-good ECM and 
recheck.

6

Wire circuit check
1) Measure resistance between “C37-25” terminal of ECM 

connector and “LT GRN” wire terminal of MAF and IAT 
sensor connector with ignition switch turned OFF.

Is resistance below 3 

Ω

?

Go to Step 7.

“LT GRN” wire is high 
resistance circuit.

7

Ground circuit check
1) Connect connectors to ECM.
2) Measure resistance between “GRY/GRN” wire terminal 

of MAF and IAT sensor connector and vehicle body 
ground with ignition switch turned OFF.

Is resistance below 3 

Ω

?

Go to Step 9.

Go to Step 8.

Step

Action

Yes

No

I5JB0A110037-02

Engine General Information and Diagnosis:  1A-92

DTC P0116: Engine Coolant Temperature Circuit Range / Performance

S5JB0A1104026

Wiring Diagram

DTC Detecting Condition and Trouble Area

8

Ground circuit check
1) Remove ECM from its bracket with ECM connectors 

connected.

2) Measure resistance between “C37-57” terminal of ECM 

connector and vehicle body ground.

Is resistance below 3 

Ω

?

“GRY/GRN” wire is 
open circuit or high 
resistance circuit. Poor 
“C37-57” connection.

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

9

IAT sensor for performance check
1) Check IAT sensor according to “Mass Air Flow (MAF) 

and Intake Air Temperature (IAT) Sensor Inspection in 
Section 1C”.

Is it in good condition?

Substitute a known-
good ECM and recheck.

Replace MAF and IAT 
sensor.

Step

Action

Yes

No

C37-57

GRY/GRN

GRY/GRN

3

1

2

5V

C37-24

PPL/YEL

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

I5JB0A110038-01

1. ECT sensor
2. ECM
3. To other sensors

DTC detecting condition

Trouble area

ECT sensor values is less than –10 

°C, 14 °F (for M16 engine) or 

–5 

°C, 23 °F (for J20 engine) while engine is running under more 

than specified engine load (more than 1000 rpm) for 2 to 1116 
min (depending on ECT at engine start) continuously from 
engine start.
(2 driving cycle detecting logic)

• ECT sensor
• ECT sensor circuit
• Thermostat
• ECM