Mitsubishi Eclipse. Manual - part 394

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-119

CIRCUIT OPERATION

• Approximately 5 volts are applied to the intake air 

temperature sensor output terminal (terminal No. 
6) from the ECM (terminal No. 62) <M/T> or PCM 
(terminal No. 64) <A/T> via the resistor in the 
ECM <M/T> or PCM <A/T>. The ground terminal 
(terminal No. 5) is grounded with ECM (terminal 
No. 34) <M/T> or PCM (terminal No. 16) <A/T>.

• The intake air temperature sensor is a negative 

temperature coefficient type of resistor. When the 
intake air temperature rises, the resistance 
decreases.

• The intake air temperature sensor output voltage 

increases when the resistance increases and 
decreases when the resistance decreases.

.

TECHNICAL DESCRIPTION

• The intake air temperature sensor converts the 

intake air temperature to a voltage.

• The ECM <M/T> or PCM <A/T> checks whether 

this voltage is within a specified range.

.

DESCRIPTIONS OF MONITOR METHODS
Intake air temperature sensor output voltage is out of 

specified range.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-120

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• 2 seconds or more have passed since the start-

ing sequence was completed.

Judgement Criteria

• Intake air temperature sensor output voltage has 

continued to be 4.5 volts or higher [corresponding 
to an air intake temperature of 

−40°C (−104°F) or 

lower] for 2 seconds.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to , Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13B-7

.

.

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

• Intake air temperature sensor failed.

• Open intake air temperature sensor circuit con-

nector damage.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

START

OUTPUT VOLTAGE < 0.2V

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 2secs

OUTPUT VOLTAGE > 4.6V

MONITORING

CONDITIONS

NO

YES

AK301424

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-121

STEP 1. Using scan tool MB991958, check data list item 13: 
Intake Air 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 or 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 

13, Intake Air Temperature Sensor.

• The intake air 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.

STEP 2. Check connector B-14 at the intake air 
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 11.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-122

STEP 3. Check the intake air temperature sensor.
(1) Disconnect the intake air temperature sensor connector 

B-14.

(2) Measure the resistance between intake air temperature 

sensor side connector terminal 5 and 6.

• There should be continuity. (0.30 − 1.0 kΩ)

Q: Is the measured resistance between 0.30 and 1.0 k

Ω?

YES : Go to Step 4.
NO :  Replace the volume airflow sensor. Then go to Step 

11.

STEP 4. Check the sensor supply voltage at intake air 
temperature sensor harness side connector B-14.
(1) Disconnect the connector B-14 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 6 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 5.

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

AK000319AB

1 2 3 4 5 6 7

INTAKE AIR TEMPERATURE
SENSOR SIDE CONNECTOR

AK300078

3

4

5

1

2

6

7

CONNECTOR: B-14

AB

B-14 (B)

HARNESS 
CONNECTOR:
COMPONENT SIDE

AKX01408

7 6 5 4 3 2 1

AG

B-14 HARNESS 
CONNECTOR: 
COMPONENT SIDE