Suzuki Grand Vitara JB627. Service manual - part 34

1A-85 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

Engine coolant temperature check
1) With ignition switch OFF install scan tool.
2) With ignition switch ON, check engine coolant 

temperature displayed on scan tool. (ECT 1)

3) Warm up engine to normal operating temperature.
4) Check engine coolant temperature displayed on scan 

tool. (ECT 2)

Is difference between ECT 1 and ECT 2 less than 1 

°

C?

Go to Step 4.

Go to Step 3.

3

Thermostat check
1) Check thermostat referring to “Thermostat Inspection in 

Section 1F”.

Is thermostat in good condition?

Go to Step 4.

Replace thermostat.

4

ECT sensor circuit check
1) With ignition switch OFF, install scan tool and disconnect 

ECT sensor connector (1).

2) With ignition switch ON, check engine coolant 

temperature displayed on scan tool.

ECT sensor temperature specifications
Signal wire terminal (2) and ground wire terminal (3) 
in ECT sensor connector are shorted by service wire 
(4): 205 

°C

Signal wire terminal (2) and ground wire terminal (3) 
in ECT sensor connector are opened: –40 

°C

Is each result satisfied its specification?

Go to Step 5.

Check ECT sensor 
signal and ground 
circuits referring to Step 
2 of “DTC P0117 / 
P0118: Engine Coolant 
Temperature Circuit 
Low / High Input”.

5

ECT sensor performance check
1) Check ECT sensor referring to “Engine Coolant 

Temperature (ECT) Sensor Inspection in Section 1C”.

Is check result as specified?

Substitute a known 
good ECM and recheck.

Replace ECT sensor.

I6JB01110032-01

Engine General Information and Diagnosis:  1A-86

DTC P0117 / P0118: Engine Coolant Temperature Circuit Low / High Input

S6JB0B1104024

Wiring Diagram
Refer to “DTC P0116: Engine Coolant Temperature Circuit Range / Performance”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

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

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

P0117: Engine Coolant Temperature Circuit Low Input
Circuit voltage of ECT sensor is less than 0.16 V for 5 seconds or longer. 
(1 driving cycle detection logic)

• ECT sensor and its circuit
• ECM

P0118: Engine Coolant Temperature Circuit High Input
Circuit voltage of ECT sensor is more than 5.0 V for 5 seconds or longer. 
(1 driving cycle detection logic)

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

Wire harness check
1) Turn ignition switch OFF position.
2) Disconnect connectors from ECT sensor and ECM.
3) Check for proper terminal connection to ECT sensor and 

ECM connectors.

4) If connections are OK, check that ECT sensor circuit is 

as follows.
• Wiring harness resistance of each ECT sensor signal 

and ground circuit is less than 3 

Ω.

• Insulation resistance of ECT sensor signal circuit is 

infinity between ECT sensor connector and vehicle 
body ground.

• Insulation resistance of wire harness is infinity 

between ECT sensor signal terminal and each other 
terminal at ECT sensor connector.

• Circuit voltage of each ECT sensor signal and ground 

circuit is 0 – 1 V with ignition switch turned ON.

Are they in good condition?

Go to Step 3.

Repair or replace 
defective wire harness.

3

ECT sensor reference voltage check
1) Connect connectors to ECM.
2) Turn ignition switch to ON position.
3) Check that ECT sensor signal voltage is 5 V between 

ECT sensor connector and vehicle body ground.

Is it in good condition?

Go to Step 4.

Substitute a known 
good ECM and recheck.

1A-87 Engine General Information and Diagnosis: 

DTC P0122 / P0123: Throttle Position Sensor (Main) Circuit Low / High Input

S6JB0B1104025

Wiring Diagram

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

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

4

ECT sensor check
1) Check ECT sensor for performance referring to “Engine 

Coolant Temperature (ECT) Sensor Inspection in 
Section 1C”.

Is it in good condition?

Substitute a known 
good ECM and recheck.

Replace ECT sensor.

Step

Action

Yes

No

BLU/BLK

BLU/BLK

BLU/BLK

BLK/RED

BLK/RED

BLK/RED

BLU

12V 5V

E23-8  

E23-16
E23-2 
E23-3 

WHT/GRN

C37-59

C37-58

C37-39

C37-73

C37-80

BLK/YEL

BLK/ORN

BLK/ORN

BLK/YEL
BLK/YEL

1

3 2

4

5

6

7

8

9

1110

12

13

14

15

16

17

18

19

20

17

18

19

20

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22

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24

25

26

27

28

29

30

31

33

34

35

36

37

38

39

40

32

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

21

22

23

24

25

26

27

28

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31

32

33

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70

71

72

73

74

75

76

77

78

79

80

81

E23

C37

BLK/ORN

C37-81

BLK/YEL

BLK/WHT

BLU/ORN

GRN

BLU/YEL

BLU/RED

BLU/BLK

E23-6 

E23-7 

E23-5 
E23-4 

C37-45

C37-46

C37-65

C37-64

BLU/RED

WHT

GRN

RED

BLK

P

S

G

8

11 10 9

13

12

7

5

2

1

4

3

6

I6JB01110033-03

P: TP sensor power supply circuit

2. Throttle actuator

6. ECM

10. “FI” fuse

S: TP sensor signal circuit

3. Throttle position sensor (main)

7. Main relay

11. “IGN” fuse

G: TP sensor ground circuit

4. Throttle position sensor (sub)

8. Fuse Box No.2

12. “IG COIL” fuse

1. Electric throttle body assembly

5. Throttle actuator control relay

9. “THR MOT” fuse

13. Ignition switch

DTC detecting condition

Trouble area

P0122: Throttle Position Sensor (Main) Circuit Low Circuit
Output voltage of TP sensor (main) is less than 0.3 V.
(1 driving cycle detection logic)

• Electric throttle body assembly
• TP sensor main circuit
• ECM

P0123: Throttle Position Sensor (Main) Circuit High Circuit
Output voltage of TP sensor (main) is more than 4.5 V.
(1 driving cycle detection logic)

Engine General Information and Diagnosis:  1A-88

DTC Troubleshooting

NOTE

• Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to 

“Precautions for DTC Troubleshooting”.

• When DTC P0122 and P0222 are indicated together, it is possible that TP sensor power supply 

circuit is open.

• When DTC P0123 and P0223 are indicated together, it is possible that TP sensor power supply 

circuit is shorted to power circuit and / or TP sensor ground circuit is open.

 

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

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

OFF.

2) Turn ON ignition switch, check “TP Sensor 1 Volt” 

displayed on scan tool when accelerator pedal is idle 
position and fully depressed.

Is displayed TP sensor value as described voltage in “Scan 
Tool Data”?

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

Go to Step 3.

3

Wire harness check
1) Turn ignition switch OFF position.
2) Disconnect connectors from TP sensor and ECM.
3) Check for proper terminal connection to electric throttle 

body assembly and ECM connectors.

4) If connections are OK, check that TP sensor (main) 

circuit is as follows.
• Wiring harness resistance of each TP sensor (main) 

signal, power supply and ground circuit is less than 
3

Ω.

• Insulation resistance of each TP sensor (main) signal 

and power supply circuit is infinity between TP sensor 
connector and vehicle body ground.

• Insulation resistance of wire harness is infinity 

between TP sensor (main) signal terminal and each 
other terminal at TP sensor connector.

• Circuit voltage of each TP sensor (main) signal, power 

supply and ground circuit is 0 – 1 V with ignition 
switch turned ON.

Are they in good condition?

Go to Step 4.

Repair or replace 
defective wire harness.

4

TP sensor circuit voltage check
1) Connect connector from ECM.
2) Turn ignition switch ON position.
3) Check that TP sensor circuit voltage is as follows.

• Between TP sensor power supply terminal and TP 

sensor ground terminal is 5 V.

• Between TP sensor (main) signal terminal and TP 

sensor ground terminal is 5 V.

Is it in good condition?

Go to Step 5.

Substitute a known 
good ECM and recheck.