MITSUBISHI LANCER 2005 Owner's Manual

TROUBLESHOOTING
ENGINE COOLING14-7
CIRCUIT OPERATION
•The cooling fan motor drive control unit is
powered from fusible link (2).
•The engine-ECU <M/T> or engine-A/T-ECU
<A/T> uses input signals from the A/C switch, the
water temperature sensor unit and the vehicle
speed sensor <M/T> or the output shaft speed
sensor <A/T> to control the speed of 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>.
•The engine-ECU <M/T> or engine-A/T-ECU
<A/T> controls the cooling fan motor drive control
unit to activate 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>.
TECHNICAL DESCRIPTION
•The cause could be a malfunction of the cooling
fan motor drive control unit power supply or earth
circuit.
•If the communication line wiring harness between
the cooling fan motor drive control unit and the
engine-ECU <M/T> or engine-A/T-ECU <A/T> is
short-circuited to earth, 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> will not rotate.
•The cause could also be a malfunction of the
cooling fan motor (L.H.). <Vehicles without A/C>
•The cause could also be a malfunction of imput
signal from the A/C switch, the water temperature
sensor unit and the vehicle speed sensor <M/T>
or the output shaft speed sensor <A/T> to the
engine-ECU <M/T> or engine-A/T-ECU <A/T>.
•The cause could also be a malfunction of the
cooling fan motor drive control unit or the
engine-ECU <M/T> or engine-A/T-ECU <A/T>.
TROUBLESHOOTING HINTS
•Malfunction of fusible link (2)
•Malfunction of fan control relay
•Malfunction of cooling fan motor (L.H.) <Vehicles
without A/C>
•Malfunction of cooling fan motor drive control unit
•Malfunction of engine-ECU <M/T> or
engine-A/T-ECU <A/T>
•Damaged wiring harness or connector
DIAGNOSIS
STEP 1. Check the cooling fan motor (L.H.).
<Vehicles without A/C>
Refer to P.14-25.
Q: Is the cooling fan motor (L.H.) in good condition?
YES :
Go to Step 2 .
NO : Replace the cooling fan motor (L.H.) (Refer
to P.14-35). Then go to Step 24 .
STEP 2. Measure the power supply voltage at
cooling fan motor drive control unit connector
A-18.
(1) Disconnect cooling fan motor drive control unit
connector A-18 and measure wiring harness side
connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between cooling fan motor
drive control unit connector A-18 terminal 3 and
body earth.
•The voltage should measure system voltage.
(4) Turn the ignition switch to the "LOCK" (OFF)
position.
(5) Connect cooling fan motor drive control unit
connector A-18.
Q: Is the measured voltage system voltage?
YES :
Go to Step 17 .
NO : Go to Step 3 .
AC100293
A-18
321
Connector: A-18
AD
AC000246AF
A-18 Connector
(Component side)

TROUBLESHOOTING
ENGINE COOLING14-8
STEP 3. Check the cooling fan motor drive
control unit connector A-18.
Q: Is the connector in good condition?
YES : .
Go to Step 4 .
NO : . Repair or replace the connector. Then go to
Step 24 .
STEP 4. Check the fusible link No.2.
Q: Is the fusible link No.2 in good condition?
YES : .
Go to Step 5 .
NO : . Replace the fusible link No.2. Then go to
Step 24 .
STEP 5. Measure the power supply voltage at fan
control relay connector A-09X.(1) Disconnect fan control relay connector A-09X
(remove the fan control relay) and measure relay
box side connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between fan control relay
connector A-09X terminal 4 and body earth.
•The voltage should measure system voltage.
(4) Turn the ignition switch to the "LOCK" (OFF)
position.
(5) Connect fan control relay connector A-09X
(install the fan control relay).
Q: Is the measured voltage system voltage?
YES :
Go to Step 8 .
NO : Go to Step 6 .
STEP 6. Check the fan control relay connector
A-09X.
Q: Is the connector in good condition?
YES :
Go to Step 7 .
NO : Repair the connector or replace the relay
box. Then go to Step 24 .
AC100293
A-18
321
Connector: A-18
AD
AC303509AB
Fusible link
No.2
Relay box
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303511AB
A-09X Connector
(Relay box side)
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X

TROUBLESHOOTING
ENGINE COOLING14-9
STEP 7. Check the harness wire between fusible
link No.2 and fan control relay connector A-09X
terminal 4.
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 8. Check the fan control relay.
Refer to P.14-24.
Q: Is the fan control relay in good condition?
YES :
Go to Step 9 .
NO : Replace the fan control relay. Then go to
Step 24 .
STEP 9. Check the fan control relay connector
A-09X.
Q: Is the connector in good condition?
YES :
Go to Step 10 .
NO : Repair the connector or replace the relay
box. Then go to Step 24 .
STEP 10. 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 11 .
NO : Repair the damaged harness wire. Then go
to Step 24 .
STEP 11. Measure the terminal voltage at fan
control relay connector A-09X.
(1) Disconnect fan control relay connector A-09X
(remove the fan control relay) and measure relay
box side connector.
(2) Turn the ignition switch to the "ON" position.
AC303509AB
Fusible link
No.2
Relay box
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
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
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X

TROUBLESHOOTING
ENGINE COOLING14-10
(3) Measure the voltage between fan control relay
connector A-09X terminal 1 and body earth.
•The voltage should measure system voltage.
(4) Turn the ignition switch to the "LOCK" (OFF)
position.
(5) Connect fan control relay connector A-09X
(install the fan control relay).
Q: Is the measured voltage system voltage?
YES : .
Go to Step 14 .
NO : . Go to Step 12 .
STEP 12. Check the J/C No.6 C-12 <L.H. drive
vehicles> or C-134 <R.H. drive vehicles>,
intermediate connector A-13 <L.H. drive
vehicles> C-111 <R.H. drive vehicles> and fan
control relay connector A-09X.
AC303517AB
A-09X Connector
(Relay box side)
AC303524
Connector: C-12 <L.H. drive vehicles>
AB
C-12
C-12
AC303525
Connector: C-134 <R.H. drive vehicles>
AB
C-134
C-134
AC303526
Connector: A-13 <L.H. drive vehicles>
AB
A-13
A-13
AC303527
Connector: C-111 <R.H. drive vehicles>
AB
C-111
C-111
615
121179
810234

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 <L.H. drive vehicles> or
C-134 terminal 33 <R.H. drive vehicles> 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 <L.H. drive vehicles>
AB
C-12
C-12
AC303525
Connector: C-134 <R.H. drive vehicles>
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 <L.H. drive vehicles> or C-111
<R.H. drive vehicles> and engine-ECU connector
C-123 <M/T> or engine-A/T-ECU connector C-122
<A/T>.
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 <L.H. drive vehicles>
AB
A-13
A-13
AC303527
Connector: C-111 <R.H. drive vehicles>
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 <M/T> or engine-A/T-ECU connector
C-122 terminal 18 <A/T>.
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 <M/T>, C-122 <A/T>
C-123 <M/T>
or
C-122 <A/T>
C-123 <M/T>
Engine-ECU <M/T> or
engine-A/T-ECU <A/T>
C-122 <A/T>
AC100293
A-18
321
Connector: A-18
AD
AC303555AB
Connector: C-123 <M/T>, C-122 <A/T>
C-123 <M/T>
or
C-122 <A/T>
C-123 <M/T>
Engine-ECU <M/T> or
engine-A/T-ECU <A/T>
C-122 <A/T>

TROUBLESHOOTING
ENGINE COOLING14-15
STEP 22. Check the cooling fan motor drive
control unit.
(1) Disconnect engine-ECU connector C-123 <M/T>
or engine-A/T-ECU connector C-122 <A/T>.
(2) Pull out connector terminal pin 21 <M/T> or 18
<A/T> 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 <M/T> or 18 <A/T>
disconnected)
•The cooling fan stops. (When connector
terminal pin 21 <M/T> or 18 <A/T> is
connected to the body earth.)
(6) Turn the ignition switch to the "OFF" position.
(7) Disconnect engine-ECU connector C-123 <M/T>
or engine-A/T-ECU connector C-122 <A/T>, and
push in connector terminal pin 21 <M/T> or 18
<A/T> 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 <M/T> or
engine-A/T-ECU <A/T> (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 <M/T>, C-122 <A/T>
C-123 <M/T>
or
C-122 <A/T>
C-123 <M/T>
Engine-ECU <M/T> or
engine-A/T-ECU <A/T>
C-122 <A/T>
AC303559
C-122 connector <A/T>
(Harness side connector: ECU side view)
AB
C-123 connector <M/T>
(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 <M/T> or the engine-A/T-ECU
<A/T> 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.). <Vehicles without A/C>
•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 <M/T>
or the output shaft speed sensor <A/T> to the
engine-ECU <M/T or engine-A/T-ECU <A/T>.
•The cause could also be a malfunction of the
cooling fan motor drive control unit or the
engine-ECU <M/T> or engine-A/T-ECU <A/T>.
TROUBLESHOOTING HINTS
•Malfunction of fan control relay
•Malfunction of cooling fan motor (L.H.) <Vehicles
without A/C>
•Malfunction of cooling fan motor drive control unit
•Malfunction of engine-ECU <M/T> or
engine-A/T-ECU <A/T>
•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