Mitsubishi Eclipse. Manual — part 160

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-133

.

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

• Engine coolant temperature sensor failed.

• Harness damage in engine coolant temperature

sensor circuit, or connector damage.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

• MB991958 (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 21:
Engine Coolant 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

21, Engine Coolant Temperature Sensor.

• The engine coolant temperature and temperature

shown with the scan tool should approximately match.

(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.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 2. Measure the sensor output voltage at engine
coolant temperature sensor connector B-11 by
backprobing.
(1) Do not disconnect the connector B-11.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 1 and ground by

backprobing.

• When engine coolant temperature is −20°C (−4°F), volt-

age should be 3.9 and 4.5 volts.

• When engine coolant temperature is 0°C (32°F), voltage

should be 3.2 and 3.8 volts.

• When engine coolant temperature is 20°C (68°F), volt-

age should be 2.3 and 2.9 volts.

• When engine coolant temperature is 40°C (104°F), volt-

age should be 1.3 and 1.9 volts.

• When engine coolant temperature is 60°C (140°F), volt-

age should be 0.7 and 1.3 volts.

• When engine coolant temperature is 80°C (176°F), volt-

age should be 0.3 and 0.9 volt.

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

YES : Go to Step 3.
NO : Go to Step 5.

STEP 3. Check connector B-11 at the engine coolant
temperature sensor for damage.
Q: Is the 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 14.

AK300404

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AK000233

B-11 HARNESS
CONNECTOR:
HARNESS SIDE

1 2

AI

AK300404

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-135

STEP 4. Using scan tool MB991958, check data list item 21:
Engine Coolant 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

21, Engine Coolant Temperature Sensor.

• The engine coolant temperature and temperature

shown with the scan tool should approximately match.

(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 : Replace the ECM or PCM. Then go to Step 14.

STEP 5. Check connector B-11 at engine coolant
temperature sensor for damage.
Q: Is the 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 14.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824

AK300404

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 6. Measure the sensor supply voltage at engine
coolant temperature sensor harness side connector B-11.
(1) Disconnect the connector B-11 and measure at the harness

side.

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

(3) Measure the voltage between terminal No. 1 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 8.
NO : Go to Step 7.

AK300404

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AK000234

B-11 HARNESS
CONNECTOR:
COMPONENT SIDE

2 1

AN