Mitsubishi Galant 9G. Manual - part 961

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-144

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.

YELLO

-GREEN

BLA

AK302836

ENGINE COOLANT
TEMPERATURE SENSOR

POWERTRAIN CONTROL MODULE(PCM)

5 V

B-104

(MU802406)

Engine Coolant Temperature Sensor Circuit

1 2

B-21

B-22

53 54 55 56

58 59 60 61 62

64 65 66 67 68 69

71 72 73 74 75

77 78 79 80 81 82

100

93 94 95

96 97 98

101 102 103 104

105 106 107 108

109 110 111 112 113

AK303036

CONNECTOR: B-104

B-104 (B)

ENGINE
COOLANT
TEMPERATURE
SENSOR

THROTTLE
BODY

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-145

CIRCUIT OPERATION

• 5-volt voltage is applied to the engine coolant

temperature sensor output terminal (terminal No.
1) from the PCM (terminal No. 93) via the resistor
in the PCM. The ground terminal (terminal No. 2)
is grounded with PCM (terminal No. 69).

• 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 PCM checks whether this voltage is within a

specified range.

DESCRIPTIONS OF MONITOR METHODS

Engine coolant 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

AK303013

CONNECTORS: B-21, B-22

PCM

AIR CLEANER

B-22 (B)

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-146

DTC SET CONDITIONS
Logic Flow Chart

Check Conditions

• 2 seconds or more have passed since the engine

starting sequence was completed.

Judgement Criteria

• Engine coolant temperature sensor output volt-

age has continued to be 0.1 volt or lower [corre-
sponding to coolant temperature of 140

°C

(284

°F) or higher] for 2 seconds.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13B-6

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.

• PCM failed.

START

OUTPUT VOLTAGE > 4.6V

OUTPUT VOLTAGE < 0.1V

END

YES

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 2secs

MONITORING

CONDITIONS?

YES

AK302388

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-147

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

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

− 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 6.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AK303037

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-104

B-104 (B)

THROTTLE
BODY

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