Mitsubishi Montero (2004+). Manual - part 154

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-103

TECHNICAL DESCRIPTION

• The intake air temperature sensor converts the 

intake air temperature to a voltage.

• The PCM checks whether this voltage is within a 

specified range.

.

DESCRIPTIONS OF MONITOR METHODS
Intake air temperature sensor output voltage is out of 

specified range.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• 2 seconds or more have passed since the start-

ing sequence was completed.

Judgement Criteria

• Intake air temperature sensor output voltage has 

continued to be 0.2 volt or lower [corresponding 
to an air intake temperature of 115

°C (239°F) or 

higher] for 2 seconds.

.

START

OUTPUT VOLTAGE < 0.2V

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 2secs

OUTPUT VOLTAGE > 4.6V

MONITORING

CONDITIONS

NO

YES

AK302922

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-104

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-4

.

.

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

• Intake air temperature sensor failed.

• Shorted intake air temperature sensor circuit, 

harness damage, or connector damage.

• PCM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check data list item 13: 
Intake Air Temperature Sensor.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to the data reading mode for item 

13, Intake Air Temperature Sensor.

• The intake air temperature and temperature shown with 

the scan tool should approximately match.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-6

.

NO :  Go to Step 2.

STEP 2. Check connector B-48 at the intake air 
temperature sensor for damage.
Q: Is the connector in good condition?

YES : Go to Step 3.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 6.

AK302970

AB

MB991911

MB991824

MB991827

AK200937

3

4

5

1

2

6

7

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-48

B-48(B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-105

STEP 3. Check the intake air temperature sensor.
(1) Disconnect the intake air temperature sensor connector 

B-48.

(2) Measure the resistance between intake air temperature 

sensor side connector terminal No. 5 and No. 6.

• There should be continuity. (0.30 − 20 kΩ)

Q: Is the measured resistance between 0.30 and 20 k

Ω?

YES : Go to Step 4.
NO :  Replace the volume airflow sensor. Then go to Step 6.

STEP 4. Check for short circuit to ground between intake 
air temperature sensor connector B-48 (terminal No.6) and 
PCM connector D-135 (terminal No. 99).
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO :  Repair it. Then go to Step 6.

AK200937

3

4

5

1

2

6

7

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-48

B-48(B)

AK000319AB

1 2 3 4 5 6 7

INTAKE AIR TEMPERATURE
SENSOR SIDE CONNECTOR

AK200937

3

4

5

1

2

6

7

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

CONNECTOR: B-48

B-48(B)

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 5. Check connector D-135 at PCM for damage.
Q: Is the connector in good condition?

YES : Replace the PCM. Then go to Step 6.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 6.

STEP 6. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function - OBD-II Drive Cycle - Procedure 6 

− 

Other Monitor 

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0112 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

PCM

D-135(GR)