Suzuki Grand Vitara JB416 / JB420 / JB419. Service manual - part 42

1A-115 Engine General Information and Diagnosis: For Petrol Engine Model

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

Is there DTC(s) other than fuel system (DTC P0171 / P0172) 
and HO2S-2 (DTC P0140)?

Go to applicable DTC 
diag. flow.

Go to Step 3.

3

HO2S-2 and its circuit check
1) Connect scan tool to DLC with ignition switch turned 

OFF.

2) Warm up engine to normal operating temperature and 

keep it at 2000 r/min. for 60 sec.

3) Repeat racing engine (Repeat depressing accelerator 

pedal 5 to 6 times continuously to enrich A/F mixture and 
take foot off from pedal to enlean it).

Does HO2S-2 output voltage indicate deflection between 
over 0.45 V and below 0.25 V?

Go to “DTC P0171 / 
P0172 / P2195 / P2196: 
Fuel System Too Lean / 
Rich / Stuck Lean / 
Stuck Rich: For Petrol 
Engine Model”.

Go to Step 4.

4

HO2S-2 ground check
1) Disconnect connector from HO2S-2 with ignition switch 

turned OFF.

2) Check for proper connection to HO2S-2 connector at 

“BLK/RED”, “RED”, “GRN” and “PNK” wire terminals.

3) If connections are OK, measure resistance between 

“GRN” wire terminal of HO2S-2 connector and engine 
ground.

Is resistance less than 3 

Ω

?

Go to Step 5.

“GRN” and/or “GRY/
GRN” wire is open or 
high resistance circuit. 
Poor “C37-57” terminal 
connection. Faulty ECM 
ground.
If they are OK, 
substitute a known-
good ECM and recheck.

5

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

turned OFF.

2) Measure resistance between “RED” wire terminal of 

HO2S-2 connector and “C37-11” terminal of ECM 
connector.

Is resistance less than 3 

Ω

?

Go to Step 6.

“RED” wire is high 
resistance circuit or 
open circuit. Poor “C37-
11” terminal connection.
If they are OK, 
substitute a known-
good ECM and recheck.

6

Wire circuit check
1) Measure resistance between “RED” wire terminal of 

HO2S-2 connector and vehicle body ground.

Is resistance infinity?

Go to Step 7.

“RED” wire is shorted to 
ground circuit.

7

HO2S-2 signal circuit check
1) Measure voltage between “RED” wire terminal of HO2S-

2 connector and vehicle body ground with ignition switch 
turned ON. 

Is voltage 0 V?

Go to Step 8.

“RED” wire is shorted to 
other circuit.

8

HO2S-2 heater circuit check
1) Check HO2S-2 heater circuit referring to “DTC P0037 / 

P0038: HO2S Heater Control Circuit Low / High 
(Sensor-2): For Petrol Engine Model”.

Is circuit in good condition?

Go to Step 9.

Repair HO2S-2 circuit.

Engine General Information and Diagnosis: For Petrol Engine Model 1A-116

DTC P0140: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-2)

S6JB0A1114035

Wiring Diagram
Refer to “DTC P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-2): For Petrol Engine 
Model”.

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

WARNING

!

 

• When performing a road test, select a place where there is no traffic or possibility of a traffic 

accident and be very careful during testing to avoid occurrence of an accident.

• Road test should be carried out by 2 persons, a driver and a tester, on a level road.

 

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 60 – 80 km/h (37 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 4 sec. or more), 

then stop vehicle and run engine at idle speed for 60 sec. or more.

6) Check DTC and pending DTC.

9

Exhaust system check
1) Check exhaust system for exhaust gas leakage.

Is it OK?

Go to Step 4 in “DTC 
P0171 / P0172 / P2195 / 
P2196: Fuel System 
Too Lean / Rich / Stuck 
Lean / Stuck Rich: For 
Petrol Engine Model”.
If it is in good condition, 
go to Step 10.

Repair leakage of 
exhaust system.

10 Air intake system check

1) Check air intake system for clog or leak.

Is it OK?

Check HO2S-2 referring 
to “Heated Oxygen 
Sensor (HO2S-2) 
Heater On-Vehicle 
Inspection: For Petrol 
Engine Model in Section 
1C”.
If it is in good condition, 
substitute a known-
good ECM and recheck.

Repair or replace air 
intake system.

Step

Action

Yes

No

DTC detecting condition

Trouble area

HO2S-2 voltage is higher than 4.5 V for 0.5 sec continuously after warming 
up engine (circuit open).
(2 driving cycle detection logic)

• HO2S-2
• HO2S-2 circuit
• ECM
• Exhaust gas leakage
• Air intake system

1A-117 Engine General Information and Diagnosis: For Petrol Engine Model

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

HO2S-2 ground check
1) Disconnect connector from HO2S-2 with ignition switch 

turned OFF.

2) Check for proper connection to HO2S-2 connector at 

“PNK”, “BLK/RED”, “GRN” and “RED” wire terminals.

3) If connections are OK, measure resistance between 

“GRN” wire terminal of HO2S-2 connector and engine 
ground.

Is resistance less than 3 

Ω

?

Go to Step 3.

“GRN” and/or “GRY/
GRN” wire is open or 
high resistance circuit. 
Poor “C37-57” terminal 
connection. Faulty ECM 
ground.
If they are OK, 
substitute a known-
good ECM and recheck.

3

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

turned OFF.

2) Measure resistance between “RED” wire terminal of 

HO2S-2 connector and “C37-11” terminal of ECM 
connector.

Is resistance less than 3 

Ω

?

Go to Step 4.

“RED” wire is high 
resistance circuit or 
open circuit. Poor “C37-
11” terminal connection.
If they are OK, 
substitute a known-
good ECM and recheck.

4

HO2S-2 signal circuit check
1) Turn ON ignition switch.
2) Measure voltage between “RED” wire terminal of HO2S-

2 connector and vehicle body ground.

Is voltage 0 V?

Go to Step 5.

“RED” wire is shorted to 
other circuit.

5

HO2S-2 heater circuit check
1) Check HO2S-2 heater circuit referring to “DTC P0037 / 

P0038: HO2S Heater Control Circuit Low / High 
(Sensor-2): For Petrol Engine Model”.

Is circuit in good condition?

Go to Step 6.

Repair HO2S-2 circuit. If 
circuit is OK, substitute 
a known-good ECM and 
recheck.

6

HO2S-2 check
1) Check HO2S-2 referring to “Heated Oxygen Sensor 

(HO2S-2) Heater On-Vehicle Inspection: For Petrol 
Engine Model in Section 1C”.

Is it in good condition?

Substitute a known-
good ECM and recheck.

Replace HO2S-2.

Engine General Information and Diagnosis: For Petrol Engine Model 1A-118

DTC P0171 / P0172 / P2195 / P2196: Fuel System Too Lean / Rich / Stuck Lean / Stuck Rich

S6JB0A1114036

Wiring Diagram

A/F Sensor Description
Refer to “A/F Sensor Description: For Petrol Engine Model”.

DTC Detecting Condition and Trouble Area

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

4

3

9

PNK

6

2

1

8

5

BLK/WHT

BLK

PNK

*GRN

C37-34

C37-32

C37-37

C37-38

BLK

BLK

BLU

WHT

C37-35

C37-31

WHT

BLK

RED/YEL

RED/BLU

PNK/BLU

BLK/YEL

10

7

11

5 V

5 V

I5JB0A110044-02

1. HO2S heater relay

4. “O2 HTR” fuse

7. Heater

10. Adjusting resistor (J20A engine)

2. Shield wire

5. “IG COIL” fuse

8. To HO2S-2 heater

11. Sensor

3. Ignition switch

6. A/F sensor

9. ECM

*: M16A engine

DTC detecting condition

Trouble area

DTC P0171:
Total fuel trim (short term fuel trim + long term fuel trim) is higher 
than specified range for 30 to 90 sec (depending on ECT) 
continuously.
(2 driving cycle detection logic)
DTC P0172:
Total fuel trim (short term fuel trim + long term fuel trim) is lower 
than specified range for 30 to 90 sec (depending on ECT) 
continuously.
(2 driving cycle detection logic)
DTC P2195:
A/F sensor output is higher than 0.7 V while vehicle is running 
constant speed and constant engine load after warmed up.
(2 driving cycle detection logic)
DTC P2196:
A/F sensor output is lower than 0.2 V while vehicle is running 
constant speed and constant engine load after warmed up.
(2 driving cycle detection logic)

• Vacuum leakage
• Exhaust gas leakage
• Fuel pressure out of specification
• Fuel injector malfunction
• A/F sensor malfunction
• MAF sensor malfunction
• ECT sensor malfunction