Mitsubishi Eclipse. Manual — part 397

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-131

.

CIRCUIT OPERATION

• 5-volt voltage is applied to the engine coolant

temperature sensor output terminal (terminal No.
1) from the ECM (terminal No. 44) <M/T> or PCM
(terminal No. 44) <A/T> via the resistor in the
ECM <M/T> or PCM <A/T>. The ground terminal
(terminal No. 2) is grounded with ECM (terminal
No. 49) <M/T> or (terminal No. 57) <A/T>.

• The engine coolant temperature sensor is a neg-

ative temperature coefficient type of resistor. It
has the characteristic that when the engine cool-
ant temperature rises the resistor decreases.

• The engine coolant temperature sensor output

voltage increases when the resistor increases
and decreases when the resistor decreases.

.

TECHNICAL DESCRIPTION

• The engine coolant temperature sensor converts

the engine coolant temperature to a voltage and
output it.

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

this voltage is within a specified range.

.

DESCRIPTIONS OF MONITOR METHODS
Engine coolant temperature sensor output voltage

does not change for specified period when
engine coolant temperature sensor output volt-
age at engine start is over 7

°C (45°F).

.

MONITOR EXECUTION
Once per driving cycle

.

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)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

.

AK300081

CONNECTOR: B-11

ENGINE
COOLANT
TEMPERATURE
SENSOR

AB

B-11 (B)

AK300244

CONNECTOR: C-55 <A/T>

AG

PCM

C-55 (GR)

AK300091

CONNECTOR: C-58 <M/T>

ECM

AC

C-58 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-132

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Engine coolant temperature was 7°C (45°F) or

more immediately before the engine was stopped
at the last drive.

• Engine coolant temperature was 7°C (45°F) or

more when the engine started.

Judgement Criteria

• Engine coolant temperature fluctuates within 1°C

(1.8

°F) after 5 minutes have passed since the

engine was started.

• However, time is not counted if any of the follow-

ing conditions are met.

1. Intake air temperature is 60

°C (140°F) or

more.

2. Volume airflow sensor output frequency is 70

Hz or less the engine without variable induc-
tion system and 60 Hz or less the engine with
variable induction system.

3. During fuel shut-off operation.

• The ECM <M/T> or PCM <A/T> monitors for this

condition once during the drive cycle.

START

END

YES

NO

NO

YES

MALFUNCTION

GOOD

300secs HAVE PASSED?

|dT| < 1˚C(1.8˚F)

MONITORING CONDITIONS?

START MEASURING THE MINIMUM AND MAXIMUM

TEMPERATURE FROM ENGINE START

CALCULATE THE DIFFERENCE OF THE MINIMUM AND

THE MAXIMUM TEMPERATURE FROM ENGINE START;dT

YES

NO

AK301425

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-133

.

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: )

• Engine coolant temperature sensor failed.

• ECM failed. <M/T>

• PCM failed. <A/T>

• Harness damage.

• Connector damage.

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 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

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-134

STEP 2. Check 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 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.

AK300435

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AK000233

B-11 HARNESS
CONNECTOR:
HARNESS SIDE

1 2

AI

AK300435

1

2

CONNECTOR: B-11

AB

B-11 (B)

HARNESS CONNECTOR:
COMPONENT SIDE