Mitsubishi Montero (2004+). Manual - part 163

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-139

TECHNICAL DESCRIPTION

• The throttle position sensor (main) outputs volt-

age which corresponds to the throttle valve open-
ing angle.

• The PCM checks whether the voltage is within a 

specified range.

.

DESCRIPTIONS OF MONITOR METHODS
throttle position sensor (main) 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 Condition

• Ignition switch "ON" position.

Judgement Criteria

• Throttle position sensor (main) output voltage 

should be 0.35 volt or less for 0.5 second.

START

YES

YES

YES

NO

NO

NO

CONTINUOUS

FAILURE FOR 0.5sec

MALFUNCTION

END

GOOD

OUTPUT VOLTAGE

< =0.35V

OUTPUT VOLTAGE > =4.8V

AK302926

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-140

.

OBD-II DRIVE CYCLE PATTERN
None.

.

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

• Throttle position sensor failed.

• Open or shorted throttle position sensor (main) 

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

• MB991658: Test Harness Set

STEP 1. Using scan tool MB991958, check data list item 79: 
Throttle Position Sensor (main).

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) Detach the intake air hose at the throttle body.
(4) Disconnect the connector of the throttle position sensor.
(5) Use test harness special tool (MB991658) to connect only 

terminals No. 1, No. 2, No. 3, and No. 4.

(6) Set scan tool MB991958 to the data reading mode for item 

79, Throttle Position Sensor (main).

• Output voltage should be between 0.3 and 0.7 volt when 

the throttle valve is fully closed with your finger.

• Output voltage should be between 4.0 volts or more 

when the throttle valve is fully open with your finger.

(7) 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 harness connector B-05 at throttle position 
sensor for damage.
Q: Is the harness 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 11.

AK302970

AB

MB991911

MB991824

MB991827

AK201174

1

6 5 4 3 2

B-05(B)

CONNECTOR: B-05

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-141

STEP 3. Measure the sensor supply voltage at throttle 
position sensor harness side connector B-05.
(1) Disconnect the connector B-05 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 2 and ground.

• Voltage should be between 4.8 and 5.2 volts.

(4) Turn the ignition switch to the "LOCK"(OFF) position.
Q:  Is the measured voltage between 4.8 and 5.2 volts?

YES : Go to Step 7.
NO :  Go to Step 4.

STEP 4. Check harness connector D-135 at PCM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 5.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 11.

AK201174

1

6 5 4 3 2

B-05(B)

CONNECTOR: B-05

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

AK201445

1

6 5 4 3 2

B-05 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

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

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-142

STEP 5. Check for open circuit and short circuit to ground 
between throttle position sensor connector B-05 (terminal 
No. 2) and PCM connector D-135 (terminal No. 106).
Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO :  Repair it. Then go to Step 11.

AK201174

1

6 5 4 3 2

B-05(B)

CONNECTOR: B-05

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

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)