Suzuki Grand Vitara JB416 / JB420. Manual - part 29

1A-65 Engine General Information and Diagnosis: 

DTC P0030: HO2S Heater Control Circuit (Sensor-1)

S5JB0A1104088

Wiring Diagram

A/F Sensor Description
Refer to “A/F Sensor Description”.

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 warm up to normal operating temperature.
4) Run engine at idle speed for 4 min. or more.
5) Check DTC and pending DTC.

8

Oil control valve check
1) Check oil control valve referring to “Oil Control Valve 

Inspection: For M16A Engine with VVT in Section 1D”.

Is it in good condition?

Replace camshaft 
timing sprocket.

Replace oil control 
valve.

Step

Action

Yes

No

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

I5JB0A110027-02

1. HO2S heater relay

4. “O2 HTR” fuse

7. Heater

10. Adjusting resistor

2. Shield wire

5. “IG COIL” fuse

8. To HO2S-2 heater

11. Sensor

3. Ignition switch

6. A/F sensor

9. ECM

*: For M16 engine

DTC detecting condition

Trouble area

Impedance of A/F sensor element is higher than or lower than 
specified range for more than 200 sec. even though A/F sensor 
heater is turned ON for more than specified time with engine 
running. (A/F sensor does not activate)
(2 driving cycle detection logic)

• A/F sensor heater circuit
• A/F sensor heater
• ECM

Engine General Information and Diagnosis:  1A-66

DTC Troubleshooting

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

 

DTC P0031 / P0032: HO2S Heater Control Circuit Low / High (Sensor-1)

S5JB0A1104015

Wiring Diagram
Refer to “DTC P0030: HO2S Heater Control Circuit (Sensor-1)”.

A/F Sensor Description
Refer to “A/F Sensor Description”.

DTC Detecting Condition and Trouble Area

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

DTC check

Is there any DTC(s) other than P0030?

Go to applicable DTC 
diag. flow.

Go to Step 3.

3

Sensor circuit check
1) Disconnect connectors from A/F sensor and ECM with 

ignition switch turned OFF.

2) Check for proper connection to A/F sensor terminals and 

ECM terminals.

3) If wire and connection are OK, measure each wire 

resistance of A/F sensor circuit (sensor and heater) 
between A/F sensor connector and ECM connector.

Is each measured wire resistance lower than 1 

Ω

?

Go to Step 4.

Repair or replace 
defective wire circuit.

4

Sensor circuit insulation check
1) Measure resistance between wire and wire at sensor 

circuit terminals of A/F sensor connector (no continuity 
check).

Is measured resistance infinity?

Substitute a known 
good A/F sensor and 
recheck.

Repair or replace 
defective circuit.

DTC detecting condition

Trouble area

P0031:
Heater control circuit voltage of A/F sensor is lower than 
specification for more than specified time continuously even 
though control duty ratio of A/F sensor heater is less than 90% 
with engine running. (Heater control duty pulse is not detected 
in its circuit of ECM)
(2 driving cycle detection logic)
P0032:
Heater control circuit voltage of A/F sensor is higher than 
specification for more than specified time continuously even 
though control duty ratio of A/F sensor heater is more than 10% 
with engine running. (Heater control duty pulse is not detected 
in its circuit of ECM)
(2 driving cycle detection logic)

• A/F sensor heater circuit
• A/F sensor heater
• ECM

1A-67 Engine General Information and Diagnosis: 

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 warm up to normal operating temperature.
4) Run engine at idle speed for 1 min. or more.
5) 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”.

 

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

A/F sensor heater circuit check
1) Disconnect connector from A/F sensor with ignition 

switch turned OFF.

2) Check for proper connection to A/F sensor connector.
3) If connection are OK, measure voltage between heater 

power terminal of A/F sensor connector and vehicle 
body ground with ignition switch turned ON.

Is measured voltage 10 – 14 V?

Go to Step 9.

Go to Step 3.

3

HO2S heater fuse check
1) Check for “O2 HTR” fuse (1) blown.

For J20 engine

For M16 engine

Is “O2 HTR” fuse in good condition?

Go to Step 5.

Go to Step 4.

1

I5JB0A110028-02

1

I5JB0A110029-02

Engine General Information and Diagnosis:  1A-68

4

A/F sensor and HO2S heater resistance check
1) Disconnect connector from HO2S-2 with ignition switch 

turned OFF.

2) Check heater resistance of A/F sensor and HO2S 

referring to “Air Fuel Ratio (A/F) Sensor On-Vehicle 
Inspection in Section 1C” and “Heated Oxygen Sensor 
(HO2S-2) Heater On-Vehicle Inspection in Section 1C”.

Are A/F sensor heater and HO2S heater in good condition?

Go to Step 6.

Replace defective 
sensor.

5

HO2S heater relay power circuit check
1) Remove integration relay No.2 (for J20 engine) (1) or 

HO2S heater relay (for M16 engine) (2) with ignition 
switch turned OFF.

2) Check for proper connection to relay connector.
3) If connection are OK, measure voltage between each 

relay power terminal of relay connector and vehicle body 
ground with ignition switch tuned ON.

For J20 engine

For M16 engine

Is each measured voltage 10 – 14 V?

Go to Step 6.

Power circuit is open.

6

Check HO2S heater relay
1) Check integration relay No.2 (for J20 engine) or HO2S 

heater relay (for M16 engine) referring to “Control Relay 
Inspection in Section 1C”.

Is it in good condition?

Go to Step 7.

Replace relay.

7

A/F sensor heater circuit check
1) Measure insulation resistance between heater terminals 

of A/F sensor connector.

Is measured resistance infinity?

Go to Step 8.

Repair or replace short 
wire.

Step

Action

Yes

No

1

I5JB0A110030-02

2

I5JB0A110031-03