Mitsubishi Galant 9G. Manual - part 973

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-192

STEP 13. Check for harness damage between engine
coolant temperature sensor connector B-104 (terminal No.
1) and PCM connector B-22 (terminal No. 93).

Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 14.
NO : Repair it. Then go to Step 14.

STEP 14. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13B-6

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0125 set?

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

AK303037

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-104

B-104 (B)

THROTTLE
BODY

AK303016

104

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-193

DTC P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

TECHNICAL DESCRIPTION

• The PCM checks the time for the cooling water

temperature to reach the judgment temperature.

DESCRIPTIONS OF MONITOR METHODS

Engine coolant temperature does not reach 77

°C

(171

°F) within specified period after cold start.

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)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

DTC SET CONDITIONS
Logic Flow Chart

START

END

YES

MALFUNCTION

GOOD

TIME HAVE PASSED

AFTER STARTING?*

ENGINE COOLANT TEMP.

>=77˚C (171˚F)

*: See DTC SET CONDITIONS-JUDGMENT CRITERIA

MONITORING

CONDITIONS?

YES

AK204044

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-194

Check Conditions

• Engine coolant temperature is between −10°C

(14

°F) and 77°C (171°F) when the engine is

started.

• The engine coolant temperature − intake air tem-

perature is 5

°C (9°F) or less when the engine is

started.

• The intake air temperature when the engine is

started

− intake air temperature is 5°C (9°F) or

less.

• The total time of the mass airflow sensor output

whose state is below 15g/sec within 300seconds.

Judgment Criteria

• The time for the engine coolant temperature to

rise to 77

°C (171°F) takes longer than approxi-

mately 7 to 16 minutes.

• The PCM monitors for this condition once during

the drive cycle.

OBD-II DRIVE CYCLE PATTERN

None.

TROUBLESHOOTING HINTS

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

• The thermostat is faulty.

• PCM failed.

DIAGNOSIS

STEP 1. Check the cooling system.

Refer to Engine Cooling Diagnosis

P.14-3

Q: Is the cooling system normal?

YES : Replace the PCM. Then check that the DTC P0128

does not reset.

NO : Repair it. Then check that the DTC P0128 does not

reset.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-195

DTC P0130: Heated Oxygen Sensor Circuit (bank 1, sensor 1)

BLA

BLUE

BLA

TO PCM

FROM MFI RELAY

PINK

AK400900

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

POWERTRAIN CONTROL
MODULE (PCM)

B-09

MU802605

B-22

Right Bank Heated Oxygen Sensor (front) Circuit

B-21

100

93 94 95

96 97 98

101 102 103 104

105 106 107 108

109 110 111 112 113

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

AK303047

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AK303013

CONNECTORS: B-21, B-22

PCM

AIR CLEANER

B-22 (B)

B-21 (B)

Content .. 971 972 973 974 ..