Mitsubishi Montero Sport (2004+). Manual - part 188

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-165

CIRCUIT OPERATION

• 5-volt voltage is applied to the engine coolant

temperature sensor output terminal (terminal No.
1) from the PCM (terminal No. 44) via the resistor
in the PCM. The ground terminal (terminal No. 2)
is grounded with PCM (terminal No. 57).

• 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 PCM checks whether this voltage is within a

specified range.

DESCRIPTIONS OF MONITOR METHODS

• Engine coolant temperature sensor output volt-

age drops from over 40

°C (104°F) to under 40°C

(104

°F) and keeps under 40°C (104°F) for 5 min-

utes.

• Engine coolant temperature sensor output volt-

age does not reach close loop enable tempera-
ture within specified period when engine coolant
temperature sensor output voltage at engine start
is under 7

°C (45°F).

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)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

AK104030

ENGINE COOLANT
TEMPERATURE SENSOR

A-67(B)

CONNECTOR: A-67

AK103738AC

CONNECTOR: C-90

PCM

C-90(GR)

AK103912AB

CONNECTOR: C-71

C-71

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-166

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.

START

END

YES

MALFUNCTION

GOOD

UNDER 40˚C (107˚F)

300secs HAVE PASSED?

YES

OVER 40˚C (107˚F)

YES

OVER 40˚C (107˚F)

AK301435

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-167

DTC SET CONDITIONS <Range/Performance problem-low input (time to reach closed loop
temperature)>

Logic Flow Chart

Check Conditions, Judgement Criteria

• About 60 − 300 seconds have passed for the

engine coolant temperature to rise to about 7

°C

(45

°F) after starting sequence was completed.

• However, time is not counted when fuel is shut

off.

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:)

• Engine coolant temperature sensor failed.

• Harness damage in engine coolant temperature

sensor circuit, or connector damage.

• PCM failed.

START

END

YES

MALFUNCTION

GOOD

TIME HAVE PASSED

AFTER STARTING?*

ENGINE
COOLANT
TEMP.

TEMP. WHERE
CLOSED LOOP
STARTS

MONITORING

CONDITIONS?

YES

*: SEE DTC SET CONDITIONS-SET CONDITIONS, JUDGMENT CRITERIA

AK301432

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-168

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.00-7

NO : Go to Step 2.

AK303629AB

MB991911

MB991827

MB991824

16-PIN

Content .. 186 187 188 189 ..