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

1

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

1

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.

AK201166

61

62

63

64

65

66

67

68

69

70

71

76

77

78

79

85

86

87

80

72

73

74

75

81

82

83

84

88

89

CONNECTOR: D-134

AB

PCM

D-134(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK201414

61
656667686970 717273
74757677787980 8182
8384

858687

8889

62

6364

D-134 HARNESS
CONNECTOR:
HARNESS SIDE

AB

AK201166

61

62

63

64

65

66

67

68

69

70

71

76

77

78

79

85

86

87

80

72

73

74

75

81

82

83

84

88

89

CONNECTOR: D-134

AB

PCM

D-134(GR)

HARNESS CONNECTOR:
COMPONENT SIDE