Mitsubishi 380. Manual — part 510

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-132

STEP 9. Check for harness damage between engine
coolant temperature sensor connector B-104 (terminal No.
1) and ENGINE-ECU connector B-20 (terminal No. 56).
Q: Is the harness wire in good condition?

YES : Then go to Step 10.
NO : Repair it. Then go to Step 11.

1

2

AK303037

HARNESS

CONNECTOR:

COMPONENT SIDE

CONNECTOR: B-104

AB

B-104 (B)

THROTTLE

BODY

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-133

STEP 10. Using diagnostic tool , check data list item 6:
Engine Coolant Temperature Sensor.

CAUTION

To prevent damage to diagnostic tool , always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set diagnostic tool to the data reading mode for item 6,

Engine Coolant Temperature Sensor.

• The engine coolant temperature and temperature

shown with the diagnostic tool should approximately
match.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor operating properly?

YES : The inspection is complete.
NO : Then go to Step 11.

STEP 11. Test the EOBD drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− EOBD Drive Cycle −

P.13A-11

.

(2) Check the diagnostic trouble code (DTC).

Q: Is DTC P0116 set?

YES : Retry the troubleshooting.
NO : The inspection is complete.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-134

DTC P0117: Engine Coolant Temperature Circuit Low Input.

CAUTION

If DTC P0117 has been set, TCL and air condi-
tioner related DTC U1120 is also set. After P0117
has been diagnosed, don't forget to erase DTC
U1120.

.

CIRCUIT OPERATION

• 5-volt voltage is applied to the engine coolant

temperature sensor output terminal (terminal No.
1) from the ENGINE-ECU (terminal No. 56) via
the resistor in the ENGINE-ECU. The ground ter-
minal (terminal No. 2) is grounded with
ENGINE-ECU (terminal No. 12).

• 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 resistance decreases.

• The engine coolant temperature sensor output

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

.

TECHNICAL DESCRIPTION

• The engine coolant temperature sensor converts

the engine coolant temperature to a voltage and
outputs it.

• The ENGINE-ECU checks whether this voltage is

within a specified range.

.

DTC SET CONDITIONS

Check Conditions

• Mass air flow.

Judgement Criteria

• Engine coolant temperature is below -39

degreeC for 0.5 second.

• MIL is activated after 2 Drive cycles.

• No limp home mode.

.

EOBD DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− EOBD Drive Cycle −

P.13A-11

.

.

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

• Engine coolant temperature sensor failed.

• Shorted engine coolant temperature sensor cir-

cuit, or connector damage.

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

DIAGNOSIS

Required Special Tools:

• : Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

AK303036

CONNECTOR: B-104

AB

B-104 (B)

ENGINE

COOLANT

TEMPERATURE

SENSOR

THROTTLE

BODY

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-135

STEP 1. Using diagnostic tool , check data list item 6:
Engine Coolant Temperature Sensor.

CAUTION

To prevent damage to diagnostic tool , always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set diagnostic tool to the data reading mode for item 6,

Engine Coolant Temperature Sensor.

• The actual engine coolant temperature and the temper-

ature shown with the diagnostic tool should approxi-
mately 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

− How to

Cope with Intermittent Malfunctions

P.00-14

.

NO : Go to Step 2.

STEP 2. 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 3.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 7.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

1

2

AK303037

HARNESS

CONNECTOR:

COMPONENT SIDE

CONNECTOR: B-104

AB

B-104 (B)

THROTTLE

BODY