2005 MITSUBISHI LANCER 23 a

TROUBLESHOOTING
ENGINE COOLING14-11
Q: Are there connectors in good condition?
YES : .
Go to Step 13 .
NO : . Repair or replace the connector. Then go to
Step 24 .
STEP 13. Check the harness wire between J/C
No.6 C-12 terminal 33 or
C-134 terminal 33 and fan
control relay connector A-09X terminal 1.
Q: Are these harness wires in good condition?
YES :
An intermittent malfunction is suspected
(Refer to GROUP 00 - How to use
troubleshooting P.00-5).
NO : Repair the damaged harness wire. Then go
to Step 24 .
STEP 14. Check the continuity between fan
control relay connector A-09X and body earth.
(1) Disconnect fan control relay connector A-09X
(remove the fan control relay) and measure relay
box side connector.
(2) Measure the resistance between fan control relay
connector A-09X terminal 3 and body earth.
•Continuity exists.
(3) Connect fan control relay connector A-09X
(install the fan control relay).
Q: Does the continuity exists?
YES :
An intermittent malfunction is suspected
(Refer to GROUP 00 - How to use
troubleshooting P.00-5).
NO : Go to Step 15 .
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303524
Connector: C-12
AB
C-12
C-12
AC303525
Connector: C-134
AB
C-134
C-134
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303533AB
A-09X Connector
(Relay box side)

TROUBLESHOOTING
ENGINE COOLING14-12
STEP 15. Check the fan control relay connector
A-09X.
Q: Is the connector in good condition?
YES :
Go to Step 16 .
NO : Repair the connector or replace the relay
box. Then go to Step 24 .
STEP 16. Check the harness wire between fan
control relay connector A-09X terminal 3 and
body earth.
Q: Is the harness wire in good condition?
YES :
An intermittent malfunction is suspected
(Refer to GROUP 00 - How to use
troubleshooting P.00-5).
NO : Repair the damaged harness wire. Then go
to Step 24 .
STEP 17. Check the continuity between cooling
fan motor drive control unit connector A-18 and
body earth.
(1) Disconnect cooling fan motor drive control unit
connector A-18 and measure wiring harness side
connector.
(2) Measure the resistance between cooling fan
motor drive control unit connector A-18 terminal 1
and body earth.
•Continuity exists.
(3) Connect cooling fan motor drive control unit
connector A-18.
Q: Dose the continuity exists?
YES :
Go to Step 20 .
NO : Go to Step 18 .
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC100293
A-18
321
Connector: A-18
AD
AC303534AB
A-18 Connector
(Wiring harness side)

TROUBLESHOOTING
ENGINE COOLING14-13
STEP 18. Check the cooling fan motor drive
control unit connector A-18.
Q: Is the connector in good condition?
YES :
Go to Step 19 .
NO : Repair or replace the connector. Then go to
Step 24 .
STEP 19. Check the harness wire between
cooling fan motor drive control unit connector
A-18 terminal 1 and body earth.
Q: Is the harness wire in good condition?
YES :
An intermittent malfunction is suspected
(Refer to GROUP 00 - How to use
troubleshooting P.00-5).
NO : Repair the damaged harness wire. Then go
to Step 24 .
STEP 20. Check the cooling fan motor drive
control unit connector A-18, intermediate
connector A-13 or C-111
and engine-ECU connector
C-123 or engine-A/T-ECU connector C-122
.
AC100293
A-18
321
Connector: A-18
AD
AC100293
A-18
321
Connector: A-18
AD
AC100293
A-18
321
Connector: A-18
AD
AC303526
Connector: A-13
AB
A-13
A-13
AC303527
Connector: C-111
AB
C-111
C-111
615
121179
810234

TROUBLESHOOTING
ENGINE COOLING14-14
Q: Are these connectors in good condition?
YES :
Go to Step 21 .
NO : Repair or replace the connector. Then go to
Step 24 .
STEP 21. Check the harness wire between
cooling fan motor drive control unit connector
A-18 terminal 2 and engine-ECU connector C-123
terminal 21 or engine-A/T-ECU connector
C-122 terminal 18 .
Q: Are these harness wires in good condition?
YES :
Go to Step 22 .
NO : Repair the damaged harness wire. Then go
to Step 24 .
AC303555AB
Connector: C-123 , C-122
C-123
or
C-122
C-123
Engine-ECU or
engine-A/T-ECU
C-122
AC100293
A-18
321
Connector: A-18
AD
AC303555AB
Connector: C-123 , C-122
C-123
or
C-122
C-123
Engine-ECU or
engine-A/T-ECU
C-122

TROUBLESHOOTING
ENGINE COOLING14-15
STEP 22. Check the cooling fan motor drive
control unit.
(1) Disconnect engine-ECU connector C-123
or engine-A/T-ECU connector C-122 .
(2) Pull out connector terminal pin 21 or 18
to disconnect connector.
(3) Reconnect the connector with connector terminal
pin still removed.
(4) Turn the ignition switch to the "ON" position.(5) Check for the cooling fan operation.
•The cooling fan rotates. (with connector
terminal pin 21 or 18
disconnected)
•The cooling fan stops. (When connector
terminal pin 21 or 18 is
connected to the body earth.)
(6) Turn the ignition switch to the "OFF" position.
(7) Disconnect engine-ECU connector C-123
or engine-A/T-ECU connector C-122 , and
push in connector terminal pin 21 or 18
to disconnect connector.
(8) Reconnect the connector with connector terminal
pin still installed.
Q: Does the cooling fan rotate? And when the
connector terminal pin is connected to the body
earth, does the cooling fan stop?
YES :
Go to Step 23 .
NO : Replace the cooling fan motor drive control
unit (Refer to P.14-35). Then go to Step 24 .
STEP 23. MUT-II/III self-diag code
Check if an MPI system self-diag code is set. (Refer
to GROUP 13A - Trouble shooting P.13A-9) <4G1>
or (Refer to GROUP 13B - Trouble shooting
P.13B-9) <4G6>.
Q: Diagnosis code set?
YES :
Inspection chart for diagnosis code (Refer
to GROUP 13A - Trouble shooting
P.13A-15) <4G1> or Inspection chart for
diagnosis code (Refer to GROUP 13B -
Trouble shooting P.13B-15) <4G6>.
NO : Replace the engine-ECU or
engine-A/T-ECU (Refer to GROUP
13A P.13A-401). Then go to Step 24 .
STEP 24. Check the symptoms.
Q: Does the cooling fan motor (L.H.) and the cooling
fan motor (R.H.) <4G1 (Vehicles with A/C)> or A/C
condenser fan motor <4G6> operate correctly?
YES :
This symptoms is complete.
NO : Return to Step 1 .
AC303555AB
Connector: C-123 , C-122
C-123
or
C-122
C-123
Engine-ECU or
engine-A/T-ECU
C-122
AC303559
C-122 connector
(Harness side connector: ECU side view)
AB
C-123 connector
(Harness side connector: ECU side view)

TROUBLESHOOTING
ENGINE COOLING14-16
INSPECTION PROCEDURE 2: Cooling Fan (L.H.) and Cooling Fan (R.H.) <4G1 (Vehicles with A/C)> or
A/C Condenser Fan <4G6> do not Change Speed or Stop
COOLING FAN (L.H.) AND COOLING FAN
(R.H.) OR A/C CONDENSER FAN DRIVE
CIRCUIT
Refer to P.14-6.
CIRCUIT OPERATION
Refer to P.14-6.
TECHNICAL DESCRIPTION
•If the communication line wiring harness between
the cooling fan motor drive control unit and the
engine-ECU or the engine-A/T-ECU
is open, the cooling fan motor (L.H.) and
the cooling fan motor (R.H.) <4G1 (Vehicles with
A/C)>, or the A/C condenser fan motor <4G6>
rotate to prevent the engine from overheating.
•If the system voltage is continuously supplied to
the cooling fan motor drive control unit by a fan
motor relay malfunction and a short circuit on the
cooling fan motor drive control unit power supply
wiring harness, the cooling fan motor (L.H.) and
the cooling fan motor (R.H.) <4G1 (Vehicles with
A/C)>, or the A/C condenser fan motor <4G6>
rotate.
•The cause could also be a malfunction of the
cooling fan motor (L.H.).
•The cause could also be a malfunction of input
signal from the A/C switch, the water temperature
sensor unit and the vehicle speed sensor
or the output shaft speed sensor to the
engine-ECU .
•The cause could also be a malfunction of the
cooling fan motor drive control unit or the
engine-ECU or engine-A/T-ECU .
TROUBLESHOOTING HINTS
•Malfunction of fan control relay
•Malfunction of cooling fan motor (L.H.) without A/C>
•Malfunction of cooling fan motor drive control unit
•Malfunction of engine-ECU or
engine-A/T-ECU
•Damaged wiring harness or connector
DIAGNOSIS
STEP 1. Check the fan control relay.
Refer to P.14-24.
Q: Is the fan control relay in good condition?
YES :
Go to Step 2 .
NO : Replace the fan control relay. Then go to
Step 8 .
STEP 2. Check the fan control relay connector
A-09X.
Q: Is the connector in good condition?
YES :
Go to Step 3 .
NO : Repair the connector or replace the relay
box. Then go to Step 8 .
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X

TROUBLESHOOTING
ENGINE COOLING14-17
STEP 3. Check the harness wire between fan
control relay connector A-09X terminal 2 and
cooling fan motor drive control unit connector
A-18 terminal 3.
Q: Is the harness wire in good condition?
YES :
Go to Step 4 .
NO : Repair the damaged harness wire. Then go
to Step 8 .
STEP 4. Check the cooling fan motor drive
control unit connector A-18, intermediate
connector A-13 or C-111
and engine-ECU connector
C-123 or engine-A/T-ECU connector C-122
.
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC100293
A-18
321
Connector: A-18
AD
AC100293
A-18
321
Connector: A-18
AD
AC303526
Connector: A-13
AB
A-13
A-13
AC303527
Connector: C-111
AB
C-111
C-111
615
121179
810234

TROUBLESHOOTING
ENGINE COOLING14-18
Q: Are these connectors in good condition?
YES :
Go to Step 5 .
NO : Repair or replace the connector. Then go to
Step 8 .
STEP 5. Check the harness wire between cooling
fan motor drive control unit connector A-18
terminal 2 and engine-ECU connector C-123
terminal 21 or engine-A/T-ECU connector
C-122 terminal 18 .
Q: Are these harness wires in good condition?
YES :
Go to Step 6 .
NO : Repair the damaged harness wire. Then go
to Step 8 .
AC303555AB
Connector: C-123 , C-122
C-123
or
C-122
C-123
Engine-ECU or
engine-A/T-ECU
C-122
AC100293
A-18
321
Connector: A-18
AD
AC303555AB
Connector: C-123 , C-122
C-123
or
C-122
C-123
Engine-ECU or
engine-A/T-ECU
C-122