Suzuki Grand Vitara JB416 / JB420 / JB419. Manual - part 39

1A-103 Engine General Information and Diagnosis: For Petrol Engine Model

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-

24” terminal.

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

between “C37-24” wire terminal of ECM connector and 
vehicle body ground.

Is voltage about 4 – 6 V?

“PPL/YEL” wire is open 
circuit. If wire and 
connection are OK, go 
to Step 5.

Go to Step 5.

5

ECT sensor harness voltage check
1) Disconnect connectors from ECM with ignition switch 

turned OFF.

2) Turn ON ignition switch.
3) Measure voltage between “PPL/YEL” wire terminal of 

ECT sensor connector and vehicle body ground.

Is voltage about 0 V?

Go to Step 6.

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

6

ECT sensor harness resistance check
1) Measure resistance between “C37-24” terminal of ECM 

connector and “PPL/YEL” wire terminal of ECT sensor 
connector with ignition switch turn OFF.

Is resistance below 3 

Ω

?

Go to Step 7.

“PPL/YEL” wire is high 
resistance circuit.

7

ECT sensor ground circuit check
1) Connect connectors to ECM.
2) Check for proper connection of ECT sensor connector at 

“GRY/GRN” wire terminal.

3) Measure resistance between “GRY/GRN” wire terminal 

of ECT sensor connector and vehicle body ground.

Is resistance below 3 

Ω

?

Go to Step 9.

Go to Step 8.

8

ECT sensor ground circuit check
1) 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

ECT sensor for performance check
1) Check ECT sensor according to “Engine Coolant 

Temperature (ECT) Sensor Inspection: For Petrol 
Engine Model in Section 1C”.

Is it in good condition?

Substitute a known-
good ECM and recheck.

Replace ECT sensor.

Step

Action

Yes

No

Engine General Information and Diagnosis: For Petrol Engine Model 1A-104

DTC P0122: Throttle Position Sensor (Main) Circuit Low

S6JB0A1114030

Wiring Diagram

DTC Detecting Condition and Trouble Area

NOTE
When DTC P0122 and P0222 are indicated together, it is possible that “WHT” wire open circuit.

 

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

12V

5V

BLU/BLK

BLU/BLK

BLK/RED

1

2

BLK/RED

BLK/RED

BLU

E23-1  

E23-60  

C37-15  

C37-29  
C37-48  

BLK/ORN

C37-58  

BLU/ORN

GRN

BLU/RED

BLU/YEL

BLU/RED

E23-16  

E23-50  

E23-17  

C37-45  

C37-44  

1-1

1-2

1-3

3

4

5

8

6

7

10

9

E23-29  

BLK/YEL

BLK/WHT

WHT/GRN

C37-30  BLK/ORN

BLK/YEL
BLK/YEL
BLK/YEL

BLU/BLK

BLU/BLK

WHT

BLK

RED

GRN

C37-53  

C37-54  

C37-40  

C37-41  

I5JB0A110041-01

1. Electric throttle body assembly

3. ECM

8. “IGN” fuse

1-1. Throttle actuator

4. Main relay

9. “IG COIL” fuse

1-2. Throttle position sensor (main)

5. Fuse box No.2

10.  Ignition switch

1-3. Throttle position sensor (sub)

6. “THR MOT” fuse

2. Throttle actuator control relay

7. “FI” fuse

DTC detecting condition

Trouble area

Output voltage of throttle position sensor (main) is less than 
0.3 V for specified time continuously.
(1 driving detection logic)

• Throttle position sensor (main) circuit
• Electric throttle body assembly
• ECM

1A-105 Engine General Information and Diagnosis: For Petrol Engine Model

DTC Confirmation Procedure

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Keep the accelerator pedal at idle position for 2 seconds.
4) Keep the accelerator pedal at fully depressed position for 2 seconds.
5) Repeat Step 3) and 4) for 3 times.
6) Check DTC.

DTC Troubleshooting

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

 

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: For 
Petrol Engine Model”.

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: For Petrol Engine Model”?

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

Go to Step 3.

3

ECM voltage check
1) Disconnect connector from electric throttle body 

assembly with ignition switch turned OFF.

2) Check for proper connection to electric throttle body 

assembly at “WHT”, “GRN” and “BLK” wire terminals.

For J20 engine

For M16 engine

3) If OK, measure voltage between “WHT” wire terminal of 

electric throttle body assembly connector and engine 
ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 6.

Go to Step 4.

"BLK"

"WHT"

"RED"

"GRN"

"BLU/YEL"

"BLU/RED"

I5JB0A110042-01

"BLU/RED"

"BLU/YEL"

"GRN"

"RED"

"WHT"

"BLK"

I5JB0A110043-01

Engine General Information and Diagnosis: For Petrol Engine Model 1A-106

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-

53” terminal.

4) If OK, measure voltage between “C37-53” terminal of 

ECM connector and engine ground with ignition switch 
turned ON.

Is voltage 4 – 6 V?

“WHT” wire is open or 
high resistance circuit.

Go to Step 5.

5

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

turned OFF.

2) Measure resistance between “C37-53” terminal of ECM 

connector and engine ground.

Is resistance infinity?

Substitute a known-
good ECM and recheck.

“WHT” wire is shorted to 
ground circuit.

6

Wire harness check
1) Measure voltage between “BLK” wire terminal of electric 

throttle body assembly connector and engine ground 
with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 9.

Go to Step 7.

7

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

turned OFF.

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

54” and “C37-41” terminals.

3) If OK, measure resistance between “GRN” and “BLK” 

wire terminals of electric throttle body assembly 
connector.

Is resistance infinity?

Go to Step 8.

“BLK” wire is shorted to 
“GRN” wire.

8

Wire harness check
1) Measure resistance between “BLK” wire terminal of 

electric throttle body assembly connector and engine 
ground with ignition switch turned OFF.

Is resistance infinity?

Substitute a known-
good ECM and recheck.

“BLK” wire is shorted to 
ground circuit.

9

Electric throttle body assembly check
1) Check throttle pedal position sensor referring to “Throttle 

Position Sensor Performance Check” under “Electric 
Throttle Body Assembly On-Vehicle Inspection: For 
Petrol Engine Model in Section 1C”.

Is output voltage within specified value?

Substitute a known-
good ECM and recheck.

Replace electric throttle 
body assembly.

Step

Action

Yes

No