Suzuki Grand Vitara JB416 / JB420. Manual — part 34

1A-85 Engine General Information and Diagnosis:

DTC P0111: Intake Air Temperature Circuit Range / Performance

S5JB0A1104023

Wiring Diagram

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

NOTE
Check to make sure that following conditions are satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10

°C (14 °F) to 80 °C (176 °F)

• Intake air temperature: –10

°C (14 °F) to 70 °C (158 °F)

• Engine coolant temperature at engine start: less than 30

°C (86 °F)

• Engine coolant temperature: 70

°C (158 °F) to 150 °C (302 °F)

• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch, clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature. (ECT approx. 90 – 95

°C, 194 – 203 °F)

4) Run engine at idle speed for 10 min. or more.
5) 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

5V

LT GRN

GRY/GRN

GRY/GRN

1

BLU/BLK

C37-25

C37-57

3

BLU

RED

C37-26

C37-27

4

2

I5JB0A110036-01

1. MAF and IAT sensor

3. To other sensors

2. ECM

4. From main relay

DTC detecting condition

Trouble area

Difference of maximum IAT minus minimum IAT is less than 0.3

°C

(32.5

°F) while ECT is over 70 °C (158 °F) after 10 min from cold

engine start (ECT is lower than 30

°C (86 °F) at engine start).

(2 driving cycle detection logic)

• High resistance circuit
• MAF and IAT sensor
• ECM

Engine General Information and Diagnosis: 1A-86

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

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

OFF.

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

Is –40

°

C (–40

°

F) or 119

°

C (246

°

F) indicated?

Go to Step 3.

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

3

Wire harness check
1) Disconnect MAF and IAT sensor connector (1) with

ignition switch turned OFF.

2) Check for proper connection to MAF and IAT sensor

connector (1) at “LT GRN” and “GRY/GRN” wire
terminals.

3) If OK, then with ignition switch turned ON, measure

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

Is measured voltage applied to “LT GRN” wire terminal about
4 – 6 V?

Go to Step 8.

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 at terminal?

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

Go to Step 5.

I5JB0A110037-02

1A-87 Engine General Information and Diagnosis:

5

Wire 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 6.

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

6

Wire circuit check
1) Turn ignition switch to ON position.
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 7.

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

7

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 8.

“LT GRN” wire is high
resistance circuit.

8

Ground circuit check
1) Connect connectors to ECM.
2) Check for proper connection of MAF and IAT sensor

connector at “GRY/GRN” wire terminal.

3) 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 5

Ω

?

Go to Step 10.

Go to Step 9.

9

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 or high resistance
circuit.
Poor “C37-57”
connection.

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

10 IAT sensor 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

Engine General Information and Diagnosis: 1A-88

DTC P0112: Intake Air Temperature Sensor Circuit Low

S5JB0A1104024

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

DTC Detecting Condition and Trouble Area

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 less than specified value

(High intake air temperature (low voltage / low 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 119

°

C (246

°

F) indicated?

Go to Step 3.

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