Hyundai Santa Fe (2006 year). Manual - part 554

FLA -282

FUEL SYSTEM

DTC P0157 HO2S CIRCUIT LOW VOLTAGE (BANK 2 / SENSOR 2)

COMPONENT LOCATION

EC466B58

HO2S [Bank 2/Sensor 2]

SCMF16176L

GENERAL DESCRIPTION

E68CCF51

The rear heated oxygen sensor is mounted on the rear side of the Catalytic Converter (warm-up catalytic converter) or
in the rear exhaust pipe, which is able to detect catalyst efficiency. The rear heated oxygen sensor (HO2S) produces a
voltage between 0V and 1V. This rear heated oxygen sensor is used to estimate the oxygen storage capability. If a catalyst
has good conversion properties, the oxygen fluctuations are smoothed by the oxygen storage capacity of the catalyst. If
the conversion provided by the catalyst is low due to aging, poisoning or misfiring, then the oxygen fluctuations are similar
to signals from the front oxygen sensor.

DTC DESCRIPTION

EE482644

Checking output signals from HO2S under detecting condition, if an output signal is below 0.04V for more than predeter-
minate time, PCM sets P0157. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2
driving cycle.

DTC DETECTING CONDITION

E814A11A

Item

Detecting Condition

Possible cause

DTC Strategy

• Monitor signal voltage

Enable Conditions

• Battery voltage ≥ 10V
• Engine running ≥ 60 sec.
• Engine warm-up state

Threshold value

• The voltage of HO2S(B2/S2) ＜ 0.04V

Diagnosis Time

• Continuous

(more than 12.5 sec. failure for every 15 sec.test)

MIL On Condition

• 2 Driving Cycles

• Poor connection
• Short to ground in harness
• HO2S(B2/S2)
• PCM

DTC TROUBLESHOOTING PROCEDURES

FLA -283

SPECIFICATION

ECAFA1F6

(REFERENCE ONLY)

Test Condition

HO2S Voltage(Sensor1)

HO2S Voltage(Sensor2)

HO2S Signal

at idle after warm-up

Signal is commonly switching

from rich to lean more than 3

times in 10 sec.

Signal is commonly above 0.6V.

HO2S signal at open circuit

(Pumping current OFF)

Approx. 0.45V

HO2S signal at open circuit

(Pumping current ON)

Approx.

3.5V

FLA -284

FUEL SYSTEM

SCHEMATIC DIAGRAM

E9EEF01F

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 -285

SIGNAL WAVEFORM AND DATA

EBC8409A

Fig) Signal waveforms of front HO2S(the upper) and rear HO2S(the lower)

SCMF16223L

After warming-up, if accelerator pedal is released suddenly around 4000rpm, the HO2S signal reading will be lower than
200mV resulting from Fuel cut-off for the moment. Conversely, if suddenly accelerator pedal is depressed, HO2S signal
reading will be around 0.6V ~1.0V. At idle, Normally HO2S signal will switch from lean to rich with 3 Hz. And as racing,
Its frequency rises.

MONITOR DTC STATUS

EC7B4E32

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

5)

Is parameter displayed "Present fault"?