Mitsubishi Lancer. Manual — part 263

TROUBLESHOOTING

ENGINE COOLING

14-18

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 <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 6 .

NO :

Repair the damaged harness wire. Then go
to Step 8 .

STEP 6. 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.

TROUBLESHOOTING

ENGINE COOLING

14-19

(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.14-33

) <4G1> (Refer to

P.14-35

) 4G6>. Then go to Step 8 .

STEP 7. 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 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 .

INSPECTION PROCEDURE 3: Cooling Fan (L.H.) does not Operate {When Cooling Fan (R.H.) <4G1> or
A/C Condenser Fan <4G6> Operate} <Vehicles with A/C>

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

The cause could be a malfunction of the cooling fan
motor (L.H.) or cooling fan motor drive control unit.

TROUBLESHOOTING HINTS

• Malfunction of cooling fan motor (L.H.)

• Malfunction of cooling fan motor drive control unit

DIAGNOSIS

STEP 1. Check the cooling fan motor (L.H.).
Refer to

P.14-24

.

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.14-33

) <4G1> (Refer to

P.14-35

)

<4G6>. Then go to Step 3 .

STEP 2. Check the cooling fan motor drive
control unit.
Refer to

P.14-22

.

Q: Is the cooling fan motor drive control unit in good

condition?
YES :

Go to Step 3 .

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 3 .

STEP 3. Check the symptoms.

Q: Do the cooling fan (L.H.) operate (when the cooling

fan (R.H.) <4G1> or A/C condenser fan <4G6>
operate)?
YES :

This symptoms is complete.

NO :

Return to Step 1 .

TROUBLESHOOTING

ENGINE COOLING

14-20

INSPECTION PROCEDURE 4: Cooling Fan (R.H.) <4G1> or A/C Condenser Fan <4G6> does not
Operate {When Cooling Fan (L.H.) Operate} <Vehicles with A/C>

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

The cause could be a malfunction of the cooling fan
motor (R.H.) <4G1> or A/C condenser fan motor
<4G6> or cooling fan motor drive control unit.

TROUBLESHOOTING HINTS

• Malfunction of cooling fan motor (R.H.) <4G1> or

A/C condenser fan motor <4G6>

• Malfunction of cooling fan motor drive control unit

DIAGNOSIS

STEP 1. Check the cooling fan motor (R.H.)
<4G1> or A/C condenser fan motor <4G6>.
Cooling fan motor (R.H.) check. (Refer to

P.14-24

)

<4G1>.
A/C condenser fan motor check. (Refer to GROUP
55

P.55A-91

) <4G6>.

Q: Is the cooling fan motor (R.H.) <4G1> or A/C

condenser fan motor <4G6> in good condition?
YES :

Go to Step 2 .

NO :

Replace the cooling fan motor (R.H.) (Refer
to

P.14-33

) <4G1> or A/C condenser fan

motor (Refer to GROUP 55

P.55A-90

)

<4G6>. Then go to Step 3 .

STEP 2. Check the cooling fan motor drive
control unit.
Refer to

P.14-22

.

Q: Is the cooling fan motor drive control unit in good

condition?
YES :

Go to Step 3 .

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 3 .

STEP 3. Check the symptoms.

Q: Do the cooling fan (R.H.) <4G1> or A/C condenser

fan <4G6> operate (when the cooling fan (L.H.)
operate)?
YES :

This symptoms is complete.

NO :

Return to Step 1 .

ON-VEHICLE SERVICE

ENGINE COOLING

14-21

ON-VEHICLE SERVICE

ENGINE COOLANT LEAK CHECK

M1141001000300

WARNING

When pressure testing the cooling system,
slowly release cooling system pressure to
avoid getting burned by hot coolant.

CAUTION

• Be sure to completely clean away any mois-

ture from the places checked.

• When the tester is taken out, be careful not to

spill any coolant.

•

ACX01844

Cap adapter

Adapter

AC

Be careful when installing and removing the
tester and when testing not to deform the
filler neck of the radiator.

1. Check that the coolant level is up to the filler neck.

Install a radiator tester and apply 160 kPa
pressure, and then check for leakage from the
radiator hose or connections.

2. If there is leakage, repair or replace the

appropriate part.

RADIATOR CAP VALVE OPENING
PRESSURE CHECK

M1141001300389

NOTE: Be sure that the cap is clean before test-
ing. Rust or other foreign material on the cap seal
will cause an improper reading.

AC211643 AB

Cap adapter

1. Use a cap adapter to attach the cap to the tester.

2. Increase the pressure until the indicator of the

gauge stops moving.
Minimum limit: 83 kPa
Standard value: 93

− 123 kPa

3. Replace the radiator cap if the reading does not

remain at or above the limit.

ENGINE COOLANT REPLACEMENT

M1141001200434

WARNING

When removing the radiator cap, use care to
avoid contact with hot coolant or steam.
Place a shop towel over the cap and turn the
cap counterclockwise a little to let the pres-
sure escape through the vinyl tube. After
relieving the steam pressure, remove the cap
by slowly turning it counterclockwise.

1. Drain the water from the radiator, heater core and

engine after unplugging the radiator drain plug
and removing the radiator cap.

AC208283 AC

Cylinder block
drain plug

<4G1>
Inlet side

AC303355

<4G6>
Inlet side

Cylinder block
drain plug

AB

2. Drain the water in the water jacket by unplugging

the drain plug of the cylinder block.

3. Remove the radiator condenser tank and drain

the coolant.

4. Drain the coolant then clean the path of the

coolant by injecting water into the radiator from
the radiator cap area.