Mitsubishi Montero (2004+). Manual - part 228

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-399

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:)

• Fuel tank temperature sensor failed.

• Open or shorted fuel tank temperature sensor cir-

cuit, harness damage, or connector damage.

• PCM failed. 

NOTE: A diagnostic trouble code (DTC) could be 
output if the engine and the radiator have been 
flushed repeatedly when the engine coolant temper-
ature was high (or the fuel tank temperature was 
high). Because this is not a failure, the DTC must be 
erased.
Make sure to test drive the vehicle in accordance 
with the drive cycle pattern in order to verify that a 
DTC will not be output.

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 
4A: 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 

4A, 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 

P.00-6

.

NO :  Go to Step 2.

STEP 2. Check connector G-03 at the fuel tank 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 12.

AK302970

AB

MB991911

MB991824

MB991827

AK200959

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2

3

AB

CONNECTOR: G-03

G-03(B)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-400

STEP 3. Check the fuel tank temperature sensor.

(1) Disconnect the fuel tank temperature sensor connector 

G-03.

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

of the fuel tank temperature sensor.

Standard value:

0.5 

− 12.0 kΩ

Q: Is the resistance between 0.5 and 12.0 k

Ω?

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

Step 12.

STEP 4. Check the continuity at fuel tank temperature 
sensor harness side connector G-03.

(1) Disconnect the connector G-03 and measure at the harness 

side.

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

ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 5.
NO :  Check connector F-07 at intermediate connector for 

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

P.00E-2

. If intermediate connector is in good 

condition, repair harness wire between fuel tank 
temperature sensor connector G-03 (terminal No. 2) 
and ground because of open circuit or harness 
damage. Then go to Step 12.

AK200959

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2

3

AB

CONNECTOR: G-03

G-03(B)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1 2 3

AK101072

FUEL TANK TEMPERATURE
SENSOR SIDE
CONNECTOR

AC

AK200959

1

2

3

AB

CONNECTOR: G-03

G-03(B)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK101071

3 2 1

G-03 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-401

STEP 5. Measure the sensor supply voltage at fuel tank 
temperature sensor harness side connector G-03.

(1) Disconnect the connector G-03 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 6.
NO :  Go to Step 10.

AK200959

1

2

3

AB

CONNECTOR: G-03

G-03(B)

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AKX01422

G-03 HARNESS 
CONNECTOR: 
COMPONENT SIDE

3 2 1

AM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-402

STEP 6. Measure the sensor supply voltage at PCM 
connector D-134 by backprobing.

(1) Do not disconnect the PCM connector D-134.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 81 and ground 

by backprobing.

• When fuel tank temperature is 0°C (32°F), voltage 

should be between 2.7 and 3.1 volts.

• When fuel tank temperature is 20°C (68°F), voltage 

should be between 2.1 and 2.5 volts.

• When fuel tank temperature is 40°C (104°F), voltage 

should be between 1.6 and 2.0 volts.

• When fuel tank temperature is 80°C (176°F), voltage 

should be between 0.8 and 1.2 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?

YES : Go to Step 7.
NO :  Go to Step 8.

STEP 7. Check connector D-134 at PCM for damage.

Q: Is the connector in good condition?

YES :  Check connector D-111 and F-07 at intermediate 

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

P.00E-2

. If intermediate connector are in 

good condition, repair harness wire between fuel level 
sensor connector G-03 (terminal No. 3) and PCM 
connector D-134 (terminal No. 81) because of open 
circuit. Then go to Step 12.

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

Connector Inspection 

P.00E-2

. Then go to Step 12.

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CONNECTOR: D-134

AB

PCM

D-134(GR)

HARNESS CONNECTOR: 
COMPONENT SIDE

AK201414

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656667686970 717273
74757677787980 8182
8384

858687

8889

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D-134 HARNESS 
CONNECTOR: 
HARNESS SIDE

AB

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CONNECTOR: D-134

AB

PCM

D-134(GR)

HARNESS CONNECTOR: 
COMPONENT SIDE