Mitsubishi Lancer. Manual — part 262

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 COOLING

14-14

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>.

AC100293

A-18

3

2

1

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>

Q: Are these harness wires in good condition?

YES :

Go to Step 22 .

NO :

Repair the damaged harness wire. Then go
to Step 24 .

TROUBLESHOOTING

ENGINE COOLING

14-15

STEP 22. Check the cooling fan motor drive
control unit.

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>

(1) Disconnect engine-ECU connector C-123 <M/T>

or engine-A/T-ECU connector 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)

(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 termi-

nal pin 21 <M/T> or 18 <A/T> disconnected)

• The cooling fan stops. (When connector ter-

minal 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.14-33

) <4G1> (Refer to

P.14-35

) <4G6>. Then go to Step 24 .

STEP 23. M.U.T.-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-384

). 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 .

TROUBLESHOOTING

ENGINE COOLING

14-16

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.14-23

.

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.

AC303510

AB

Fan control relay

Relay box

Connector: A-09X

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 .

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.

AC303510

AB

Fan control relay

Relay box

Connector: A-09X

A-09X

AC100293

A-18

3

2

1

Connector: A-18

AD

TROUBLESHOOTING

ENGINE COOLING

14-17

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 <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

3

2

1

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

6

1

5

12

11

7

9

8

10

2 3

4

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>

Q: Are these connectors in good condition?

YES :

Go to Step 5 .

NO :

Repair or replace the connector. Then go to
Step 8 .