Hyundai Santa Fe (2006 year). Manual - part 519

FLA -142

FUEL SYSTEM

Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others.

NO

▶ Substitute with a known - good HO2S(B2/S1) and check for proper operation.
If the problem is corrected, go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR

EBC231F8

Refer to DTC P0050.

DTC TROUBLESHOOTING PROCEDURES

FLA -143

DTC P0056 HO2S HEATER CONTROL CIRCUIT (BANK 2 / SENSOR 2)

COMPONENT LOCATION

E817128B

HO2S [Bank 2/Sensor 2]

SCMF16176L

GENERAL DESCRIPTION

EE20DCF2

The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850 C(662 to 1562 F). The
HO2S heater greatly decreases the amount of time required for fuel control to become active. The ECM provides a pulse
width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is
low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current
drops gradually.

DTC DESCRIPTION

E95D0768

Checking current from HO2S under detecting condition,if the heater current is below a certain threshold for more than
predeterminate time, PCM sets P0056. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consec-
utive 2 driving cycle.

DTC DETECTING CONDITION

E8E45268

Item

Detecting Condition

Possible cause

DTC Strategy

• Monitor the current through the heater

Enable Conditions

• Engine Running ＞ 60 sec.
• Heater Duty Cycle ＞ 18%
• Max. Duty Cycle - Min. Duty Cycle ＜ 5%

Threshold value

• Filtered Heater Current ＜ threshold value

Diagnosis Time

• Continuous

(More than 2.5 second failure for every 5 second test )

MIL On Condition

• 2 Driving Cycles

• Poor connection
• HO2S(B2/S2)
• PCM

FLA -144

FUEL SYSTEM

SPECIFICATION

E28FDF13

(REFERENCE ONLY)

Condition

Current(A)

Heater Current at 13.5V, 450℃(842 F) Exhaust

0.52 ± 0.1

SCHEMATIC DIAGRAM

E14CB6D5

HO2S [Bank 1/Sensor 1]
HO2S [Bank 2/Sensor 1]

PCM

C91-1,2

C30-B

PCM (C30-B)

HO2S [B1/S1] (C91-1)

1

2

1

21

2

22

3

23

4

24

5

25

6

26

7

27

8

28

9

29

10

30

11

31

12

32

13

33

14

34

15

35

16

36

17

37

18

38

19

39

20

40

41

61

42

62

43

63

44

64

45

65

46

66

47

67

48

68

49

69

50

70

51

71

52

72

53

73

54

74

55

75

56

76

57

77

58

78

59

79

60

80

Battery Voltage (B+)

Main Relay

3

4

PCM C30-B (30)

HO2S [B1/S1] Signal

Sensor ground

PCM C30-B (49)

Main Relay

3

4

1

2

49 - HO2S [B1/S1] Signal

30 - GND

70 - Heater [B1/S1] Control

HO2S [B2/S1] (C91-2)

Main Relay

3

4

1

2

51 - HO2S [B2/S1] Signal

28 - GND

67 - Heater [B2/S1] Control

HO2S [B1/S2] (C91-3)

Main Relay

3

4

1

2

50 - HO2S [B1/S2] Signal

31 - GND

74 - Heater [B1/S2] Control

HO2S [B2/S2] (C91-4)

Main Relay

3

4

1

2

52 - HO2S [B2/S2] Signal

29 - GND

73 - Heater [B2/S2] Control

1

2

3

4

PCM C30-B (28)

HO2S [B2/S1] Signal

Sensor ground

PCM C30-B (51)

Battery Voltage (B+)

Main Relay

PCM C30-B (67)

Heater

 [B2/S1] Control

1

2

3

4

PCM C30-B (31)

HO2S [B1/S2] Signal

Sensor ground

PCM C30-B (50)

Battery Voltage (B+)

Main Relay

PCM C30-B (74)

Heater

 [B1/S2] Control

1

2

3

4

PCM C30-B (29)

HO2S [B2/S2] Signal

Sensor ground

PCM C30-B (52)

Battery Voltage (B+)

Main Relay

PCM C30-B (73)

Heater

 [B2/S2] Control

[CIRCUIT DIAGRAM]

[HARNESS CONNECTORS]

[CONNECTION INFORMATION]

Terminal

Connected to

Function

Terminal

Connected to

Function

Terminal

Connected to

Function

Terminal

Connected to

Function

HO2S [B1/S1]

HO2S [B2/S1]

HO2S [B1/S2]

HO2S [B2/S2]

PCM C30-B (70)

Heater

 [B1/S1] Control

HO2S [Bank 1/Sensor 2]
HO2S [Bank 2/Sensor 2]

C91-3,4

2

1

4

3

1

2

3

4

SCMF16110L

DTC TROUBLESHOOTING PROCEDURES

FLA -145

SIGNAL WAVEFORM AND DATA

E0BCDEF2

Fig1) The signal waveforms of front HO2S(the upper) and heater(the lower) at idle
Fig2) The signal waveforms of rear HO2S(the upper) and heater(the lower) at idle

Fig. 1

Fig. 2

SCMF16158L

The HO2S requires a minimum temperature to provide a closed loop fuel control system. So the HO2S contains a heater
element to reduce its warm-up time and ensure its performance during all driving conditions. The PCM controls this heater
element by duty cycle. The main relay supplies voltage to the heater and the PCM provides a ground circuit for activating
the heater.

MONITOR DTC STATUS

E22844FA

1.

Check DTC Status

1)

Connect scantool to Data Link Connector(DLC).

2)

IG "ON".

3)

Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC’s information from the
DTCs menu

4)

Read "DTC Status" parameter.

SCMF16159L