Mitsubishi Montero Sport (2004+). Manual - part 191

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-177

Check Conditions

• Engine coolant temperature is between −10°C 

(14

°F) and 77°C (171°F) when the engine is 

started.

• The engine coolant temperature − intake air tem-

perature is 5

°C (9°F) or less when the engine is 

started.

• The intake air temperature when the engine is 

started 

− intake air temperature is 5°C (9°F) or 

less.

• The volume airflow sensors output frequency (50 

- 100Hz or less) state for 300 seconds or less.

Judgment Criteria

• The time for the engine coolant temperature to 

rise to 77

°C (171°F) takes longer than approxi-

mately 12 to 20 minutes.

• The PCM monitors for this condition once during 

the drive cycle.

.

OBD-II DRIVE CYCLE PATTERN
None.

.

TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:

• The thermostat is faulty.

• PCM failed.

DIAGNOSIS

STEP 1. Check the cooling system.
Refer to GROUP 14, Engine Cooling Diagnosis 

P.14-2

.

Q: Is the cooling system normal?

YES : Replace the PCM. Then check that the DTC P0128 

does not reset.

NO :  Repair it. Then check that the DTC P0128 does not 

reset.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-178

DTC P0130: Heated Oxygen Sensor Circuit (bank 1, sensor 1)

BLA

CK

BLA

CK

WHITE

BLA

CK-RED

AK000444

Right Bank Heated Oxygen Sensor (front) Circuit

4

POWERTRAIN CONTROL MODULE (PCM)

12

2

3

1

18

57

72

RIGHT BANK HEATED OXYGEN
SENSOR (FRONT)

TO PCM

FROM MFI RELAY

C-90

C-91

1 2
3 4

A-07
MU802605

47

41

42 43

48 49 50 51 52 53 54 55 56 57

46

45

44

58

59

60 61 62 63

64 65 66

C-90
(MU803781)

71

76

77

72 73 74

75

79 80

78

81

87 88

89

91

90

92

97

98

82

93

83

94

84 85

95

86

96

C-91
(MU803782)

1

10

2 3 4 5 6 7 8 9

11

12 13 14 15 16 17 18 19 20 21 22

23 24 25 26 27 28 29 30 31 32 33

C-71

JOINT
CONNECTOR (4)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-179

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 72) from the output terminal (terminal 
No. 4) of the right bank heated oxygen sensor 
(front).

• Terminal No. 2 of the right bank heated oxygen 

sensor (front) is grounded with PCM (terminal 
No. 57).

.

TECHNICAL DESCRIPTION

• The right bank heated oxygen sensor (front) 

detects the concentration of oxygen in the 
exhaust gas; it converts those data to voltage, 
and inputs the resulting signals to the PCM.

• When the right bank heated oxygen sensor 

(front) begins to deteriorate, the heated oxygen 
sensor signal response becomes poor.

• The PCM forcibly varies the air/fuel mixture to 

make it leaner and richer, and checks the 
response speed of the right bank heated oxygen 
sensor (front). In addition, the PCM also checks 
for an open circuit in the right bank heated oxy-
gen sensor (front) output line.

.

DESCRIPTIONS OF MONITOR METHODS
 Right bank heated oxygen sensor (front) circuit is 

switched to 5 volts intentionally when oxygen 
sensor output is low, and detects the malfunction 
if the output voltage changes to equal or greater 
than 4.5 volts. The above procedure is repeated 
when oxygen sensor is inactive.

.

MONITOR EXECUTION
Continuous

.

AK200489

A-07(B)

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AB

CONNECTOR: A-07

AK103912AB

CONNECTOR: C-71

C-71

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-180

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Heated oxygen sensor heater (front) monitor

• Misfire monitor

• Fuel system monitor

Sensor (The sensor below is determined to be 

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.