Mitsubishi Lancer Evolution X. Manual - part 307

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-293

DTC SET CONDITIONS
Logic Flow Chart

.

Check Condition

• 2 seconds or more have passed since the engine 

starting sequence was completed.

Judgement Criterion

• Sensor output voltage has continued to be 4.6 

volts or higher for 2 seconds.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 23 

P.13A-9

.

.

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

• Fuel tank temperature sensor failed.
• Open fuel tank temperature sensor circuit, har-

ness damage, or connector damage.

• ECM failed. 

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

• MB992110: Power Plant ECU Check Harness

AK700478

Good

Malfunction

End

No

No

No

No

Yes

Yes

Yes

Yes

Continuous

failure for 2secs

Monitoring
conditions

Start

Output voltage

< 0.1V

Output voltage

> 4.6V

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 1. Using scan tool MB991958, check data list item 53: 
Fuel Tank 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 

53, Fuel Tank Temperature Sensor.

• Approximately the same as the ambient air temperature 

when the engine is cooled.

(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 :  Go to Step 2.

STEP 2. Check harness connector D-22 at the fuel tank 
temperature 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 10.

STEP 3. Check the fuel tank temperature sensor.
(1) Disconnect the fuel tank temperature sensor connector 

D-22.

(2) Measure the resistance between terminal No. 1 and No. 3 

of the fuel tank temperature sensor.

Standard value:

0.5 − 12.0 kΩ

Q: Is the measured resistance between 0.5 and 12.0 kΩ?

YES : Go to Step 4.
NO :  Replace the fuel tank temperature sensor. Then go to 

Step 10.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

1

2 3

4

5

AK203165

Fuel tank temperature
sensor connector

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 4. Check the sensor supply voltage at fuel tank 
temperature sensor harness side connector D-22.
(1) Disconnect the connector D-22 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 3 and ground.

• Voltage should be between 4.5 and 4.9 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?

YES : Go to Step 7.
NO :  Go to Step 5.

STEP 5. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 6. 
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 10.

1

2

3

4

5

AK203167

D-22 harness 
connector: 
component side

AE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 6. Check the sensor supply voltage at ECM 
connector B-10 by using power plant ECU check harness 
special tool MB992110.
(1) Disconnect all ECM connectors. Connect the power plant 

ECU check harness special tool MB992110 between the 
separated connectors.

(2) Disconnect the fuel tank temperature sensor connector 

D-22.

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

(4) Measure the voltage between terminal No. 115 and ground.

• Voltage should be between 4.5 and 4.9 volts.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.5 and 4.9 volts?

YES : Check harness connector C-47 at intermediate 

connector for damage, and repair or replace as 
required. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. If the intermediate connector is in 

good condition, repair the harness wire between fuel 
tank temperature sensor connector D-22 (terminal 
No. 3) and ECM connector B-10 (terminal No. 115) 
because of open circuit. Then go to Step 10.

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-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 10.

STEP 7. Check the continuity at fuel tank temperature 
sensor harness side connector D-22.
(1) Disconnect the connector D-22 and measure at the harness 

side.

(2) Check for the continuity between terminal No. 1 and 

ground.

• Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 8.
NO :  Repair harness wire between fuel tank temperature 

sensor connector D-22 (terminal No. 1) and ground 
because of open circuit or harness damage. Then go 
to Step 10.

AK604171

ECM

AB

Body side harness 

MB992110

82 81 80 79 78 77 76 75 74 73 72 71

94 93 92 91 90 89 88 87 86 85 84 83

99 98 97 96 95

100

101

102

103

104

105

106

112

113

114

109 108

107

110

111

115

116

117

118

AK604190 AB

Power plant ECU
check harness connector

1

2

3

4

5

AK203166

D-22 harness 
connector: 
component side

AF