Mitsubishi Evolution X. Manual - part 292

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-145

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, check data list item 8: 
Manifold Absolute Pressure 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 

8, Manifold Absolute Pressure Sensor.

• When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).

• When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).

• When altitude is 1,200 m (3,937 feet), 88 kPa (26.0 

in.Hg).

• When altitude is 1,800 m (5,906 feet), 81 kPa (23.9 

in.Hg).

(4) Start the engine.

• When the engine is idling, 31 − 45 kPa (9.1 − 13.3 in.Hg).

• When the engine is suddenly revved, manifold absolute 

pressure varies.

(5) 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 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

NO :  Go to Step 2.

STEP 2. Measure the ground voltage at manifold absolute 
pressure sensor connector B-18 by backprobing.
(1) Do not disconnect the connector B-18.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 2 and ground by 

backprobing.

• Voltage should be 0.5 volt or less.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage 0.5 volt or less?

YES : Go to Step 6.
NO :  Go to Step 3.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

3

2

1

AK203038

B-18 harness 
connector: 
harness side

AM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 3. Check harness connector B-18 at the manifold 
absolute pressure sensor and harness connector B-09 at 
ECM for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 7.

STEP 4. Check for open circuit between manifold absolute 
pressure sensor connector B-18 (terminal No. 2) and ECM 
connector B-09 (terminal No. 46).
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO :  Repair it. Then go to Step 7.

STEP 5. Using scan tool MB991958, check data list item 8: 
Manifold Absolute Pressure Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991958 to the data reading mode for item 

8, Manifold Absolute Pressure Sensor.

• When altitude is 0 m (0 foot), 101 kPa (29.8 in.Hg).

• When altitude is 600 m (1,969 feet), 95 kPa (28.1 in.Hg).

• When altitude is 1,200 m (3,937 feet), 88 kPa (26.0 

in.Hg).

• When altitude is 1,800 m (5,906 feet), 81 kPa (23.9 

in.Hg).

(3) Start the engine.

• When the engine is idling, 31 − 45 kPa (9.1 − 13.3 in.Hg).

• When the engine is suddenly revved, manifold absolute 

pressure varies.

(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 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

NO :  Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-12

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 7.

STEP 6. Check harness connector B-18 at the manifold 
absolute pressure sensor and harness connector B-09 at 
ECM for damage.
Q: Is the harness connector in good condition?

YES : Replace the manifold absolute pressure sensor. Then 

go to Step 7.

NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 7.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 7. 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 − Pattern 23 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0108 set?

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

DTC P0111: Intake Air Temperature Circuit Range/Performance Problem (sensor 1)

.

AK704241

71 72 73 74 75 76 77 78 79 80 81 82

83 84 85 86 87 88 89 90 91 92 93 94

95 96 97 98 99

100 101 102 103 104

112 113 114

109

108

107

110 111

115 116

106

105

118

117

3 4

2

1

AB

88

89

INTAKE AIR TEMPERATURE
SENSOR 1 (INTEGRATED IN
MASS AIRFLOW SENSOR)

ENGINE
CONTROL
MODULE

4

1

5 V

INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT

VIOLET

BLA

CK-BLUE

A-07

(MU805110)

B-10

AK704234

Connector: A-07

Intake air temperature
sensor 1 (integrated in mass
airflow sensor)

A-07 (GR)

AC

AK704235 AB

Connector: B-10

ECM

B-10 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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CIRCUIT OPERATION

• Approximately 5 volts are applied to the intake air 

temperature sensor 1 output terminal (terminal 
No. 1) from the ECM (terminal No. 89) via the 
resistor in the ECM. The ground terminal (termi-
nal No. 4) is grounded with ECM (terminal No. 
88).

• The intake air temperature sensor 1 is a negative 

temperature coefficient type of resistor. When the 
intake air temperature rises, the resistance 
decreases.

• The intake air temperature sensor 1 output volt-

age increases when the resistance increases and 
decreases when the resistance decreases.

.

TECHNICAL DESCRIPTION

• The intake air temperature sensor 1 converts the 

intake air temperature to a voltage.

• The ECM checks whether this voltage is within a 

specified range.

.

DESCRIPTIONS OF MONITOR METHODS

Intake air temperature sensor 1 output voltage does 

not change when specified go/stop operations 
are repeated.

.

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)

• Engine coolant temperature sensor

.