Mitsubishi Galant (2004+). Manual - part 1121

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-177

DTC SET CONDITIONS <Range/Performance problem - drift>

Logic Flow Chart

.

Check Conditions, Judgement Criteria

• Engine coolant temperature decreases from 

higher than 40

°C (104°F) to lower than 40°C 

(104

°F).

• Then the engine coolant temperature has contin-

ued to be 40

°C (104°F) or lower for 5 minutes.

.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13B-5

.

.

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.

• PCM failed.

START

END

NO

NO

YES

YES

MALFUNCTION

GOOD

UNDER 40˚C (107˚F)

300SECS HAVE PASSED?

NO

YES

OVER 40˚C (107˚F)

YES

OVER 40˚C (107˚F)

NO

AK302387

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-178

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-179

STEP 2. Measure the sensor output voltage at engine 
coolant temperature sensor connector B-104 by 
backprobing.
(1) Do not disconnect the connector B-104.
(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 between 3.9 and 4.5 volts.

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

should be between 3.2 and 3.8 volts.

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

age should be between 2.3 and 2.9 volts.

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

age should be between 1.3 and 1.9 volts.

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

age should be between 0.7 and 1.3 volts.

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

age should be between 0.3 and 0.9 volt.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage within the specified range?

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

STEP 3. Check harness connector B-104 at the engine 
coolant temperature sensor 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 14.

1

2

AK303037

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-104

AB

B-104 (B)

THROTTLE
BODY

AK303038

2

1

AB

B-104 HARNESS 
CONNECTOR: 
HARNESS SIDE

1

2

AK303037

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-104

AB

B-104 (B)

THROTTLE
BODY

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-180

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 PCM. Then go to Step 14.

STEP 5. Check harness connector B-104 at engine coolant 
temperature sensor 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 14.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

1

2

AK303037

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-104

AB

B-104 (B)

THROTTLE
BODY