ECU MITSUBISHI LANCER 2005 Workshop Manual

WARNINGS REGARDING SERVICING OF SUPPLEMENTAL
RESTRAINT SYSTEM (SRS) EQUIPPED VEHICLES
(1) Improper service or maintenance of any component of the SRS or any SRS-related component,
can lead to personal injury or death to service personnel (from inadvertent firing of the air bag)
or to the driver and passenger (from rendering the SRS inoperative).
(2) The SRS components and seat belt with pretensioner should not be subjected to heat, so
remove the SRS-ECU, driver’s and front passenger’s air bag modules, clock spring, side air bag
modules, and seat belt -pre-tensioner before drying or baking the vehicle after painting.
• SRS-ECU, air bag module and clock spring 93°C or more
• Seat belt with pre-tensioner: 90°C or more
(3) Service or maintenance of any SRS component or SRS-related component must be performed
only at an authorized MITSUBISHI dealer.
(4) MITSUBISHI dealer personnel must thoroughly review this Manual, and especially its GROUP
52B - Supplemental Restraint System (SRS), before beginning any service or maintenance of
any component of the SRS or any SRS-related component.
NOTE
Section titles with asterisks (*) in the table of contents in each group indicate operations requiring warnings.

TROUBLESHOOTING
ENGINE COOLING14-6
INSPECTION PROCEDURE FOR
TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1: Cooling Fan (L.H.) and Cooling Fan (R.H.) <4G1 (Vehicles with A/C)> or
A/C Condenser Fan <4G6> do not Operate
Wire colour code
B : Black LG : Light green
G : Green L : Blue
W : White Y : Yellow
SB : Sky blue BR : Brown
O : Orange GR : Gray
R : Red P : Pink V : Violet
FAN CONTROL
RELAY
A-09XENGINE CONTROL
RELAY
B-16X
AC303577
A-18-1
COOLING FAN
MOTOR (L.H.) COOLING FAN
MOTOR (R.H.)
<4G1 (VEHICLES
WITH A/C>
OR
A/C CONDENSER
FAN MOTOR <4G6>A-18-2 A-18
COOLING FAN
MOTOR DRIVE
CONTROL UNIT1 A-13
12 C-111 ENGINE-ECU OR
ENGINE-A/T-ECU
21 C-123
18 C-122
615
121179
810234
(MU802322) (MU801824)
C-123
(MU803784)C-122
(MU802611)A-13
C-111L
L
2
2211
1B L2
3 4 B-W FUSIBLE
LINK No.2
B3 1 R-Y R-Y
8 A-13
11 C-111
615
121179
810234
(MU802611)
J/C (6)
C-12
C-134 R-Y
3328
A-13
C-111
Cooling Fan (L.H.) and Cooling Fan (R.H.) or A/C Condenser Fan Drive Circut
AB

TROUBLESHOOTING
ENGINE COOLING14-7
CIRCUIT OPERATION
•The cooling fan motor drive control unit is
powered from fusible link (2).
•The engine-ECU or engine-A/T-ECU
uses input signals from the A/C switch, the
water temperature sensor unit and the vehicle
speed sensor or the output shaft speed
sensor 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 or engine-A/T-ECU
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 or engine-A/T-ECU 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.).
•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
or the output shaft speed sensor to the
engine-ECU or engine-A/T-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 fusible link (2)
•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 cooling fan motor (L.H.).

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 COOLING14-13
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

TROUBLESHOOTING
ENGINE COOLING14-19
STEP 6. 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 7 .
NO : Replace the cooling fan motor drive control
unit (Refer to P.14-35). Then go to Step 8 .
STEP 7. 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 8 .
STEP 8. 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)