Mitsubishi Galant. Manual — part 212

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-73

DTC P0116: Engine Coolant Temperature Circuit Range/Performance Problem

CIRCUIT OPERATION

•

5-volt voltage is applied to the engine coolant
temperature sensor output terminal (terminal 1)
from the PCM (terminal 44) via the resistor in
the PCM. The ground terminal (terminal 2) is
grounded with PCM (terminal 57).

•

The engine coolant temperature sensor is a
negative temperature coefficient type of resistor.
It has the characteristic that when the engine
coolant temperature rises the resistor decreases.

•

The engine coolant temperature sensor output
voltage increases when the resistor increases
and decreases when the resistor decreases.

AK000499

1 2

BLA

CK

YELLO

W

-GREEN

57

44

POWERTRAIN CONTROL
MODULE(PCM)

ENGINE COOLANT
TEMPERATURE SENSOR

B-13
(MU802406)

2

1

5V

C-40
(MU803781)

42 43
48 49 50 51 52 53 54 55 56 57

46

45

44

58 59

60 61 62 63

64 65 66

47

41

ACX02490

CONNECTOR:B-13

ENGINE
COOLANT
TEMPERATURE
SENSOR

AG

AK000280

CONNECTOR : C-40

PCM

AV

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-74

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.

DTC SET CONDITIONS

Check Conditions

•

Two seconds or more have passed since the
staring sequence was completed.

Judgement Criteria

•

Engine coolant temperature sensor output
voltage has continued to be 4.6 volts or higher
[corresponding to a coolant temperature of -45

°

C

(-49

°

F) or lower] for 2 seconds.

or

•

Engine coolant temperature sensor output
voltage has continued to be 0.1 volt or lower
[corresponding to a coolant temperature of 140

°

C (284

°

F) or higher] for 2 seconds.

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

•

Engine coolant temperature sensor failed.

•

Open or shorted engine coolant temperature
sensor circuit, or loose connector.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 21:
Engine Coolant Temperature Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 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.00-8

).

NO : Go to Step 2.

STEP 2. Check connector B-13 at the engine coolant
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.

AC003081 AB

16 PIN

MB991502

ACX02490

CONNECTOR:B-13

ENGINE
COOLANT
TEMPERATURE
SENSOR

AG

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-75

STEP 3. Check the sensor supply voltage at engine
coolant temperature sensor harness side connector B-13.
(1) Disconnect the connector B-13 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 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 voltage normal?

YES : Go to Step 6.
NO : Go to Step 4.

STEP 4. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 11.

STEP 5. Check for open circuit between engine coolant
temperature sensor connector B-13 terminal 1 and PCM
connector C-40 terminal 44.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 11.
NO : Repair it. Then go to Step 11.

AK000234

B-13 HARNESS
SIDE CONNECTOR

1

2

AD

AK000280

CONNECTOR : C-40

PCM

AV

ACX02490

CONNECTOR:B-13

ENGINE
COOLANT
TEMPERATURE
SENSOR

AG

AK000280

CONNECTOR : C-40

PCM

AV

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-76

STEP 6. Check the continuity at engine coolant
temperature sensor harness side connector B-13.
(1) Disconnect the connector B-13 and measure at the harness

side.

(2) Check for the continuity between terminal 2 and ground.

•

Should be less than 2 ohm.

Q: Is the continuity normal?

YES : Go to Step 9.
NO : Go to Step 7.

STEP 7. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 8.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 11.

STEP 8. Check for open circuit between engine coolant
temperature sensor connector B-13 terminal 2 and PCM
connector C-40 terminal 57.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 11.
NO : Repair it. Then go to Step 11.

AK000235

B-13 HARNESS
SIDE CONNECTOR

1

2

AD

AK000280

CONNECTOR : C-40

PCM

AV

ACX02490

CONNECTOR:B-13

ENGINE
COOLANT
TEMPERATURE
SENSOR

AG

AK000280

CONNECTOR : C-40

PCM

AV