Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual - part 345

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-11

STEP 9. Check the circuit at ECM connector C-49 <2.4L-M/
T>, C-51 <3.0L-M/T>or PCM connector C-50 <2.4L-A/T>, C-
52 <3.0L-A/T>.
(1) Connect ECM connector C-49 <2.4L-M/T>, C-51 <3.0L-M/

T> or PCM connector C-50 <2.4L-A/T>, C-52 <3.0L-A/T>.

(2) Start the engine and allow it to idle.
(3) Measure the voltage between terminal number 21 <2.4L-M/

T> or 18 <2.4L-A/T, 3.0L> and ground.

Q: Is the voltage 0.7 volt or more when the radiator fan is

operating?
YES : Go to Step 11.
NO : Go to Step 10.

AC000254

CONNECTOR C-49

CONNECTOR
C-50, C-51, C-52

<2.4L-M/T>

<2.4L-A/T, 3.0L>

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-12

STEP 10. Check the harness wire between ECM connector
C-49 <2.4L-M/T>, C-51 <3.0L-M/T>or PCM connector C-50
<2.4L-A/T>, C-52 <3.0L-A/T> and fan controller connector
A-30.
NOTE: If intermediate connector C-07 is damaged, repair or
replace it. Refer to GROUP 00E, Harness Connector
Inspection

P.00E-2

Q: Are the harness wires between ECM connector C-49

<2.4L-M/T>, C-51 <3.0L-M/T>or PCM connector C-50
<2.4L-A/T>, C-52 <3.0L-A/T> and fan controller
connector A-30 damaged?
YES : Repair or replace them, then go to Step 12.
NO : Go to Step 11.

AC000244

CONNECTOR: C-07

AC000245 AE

CONNECTOR:
C-49 <2.4L-M/T>, C-50 <2.4L-A/T>
C-51 <3.0L-M/T>, C-52 <3.0L-A/T>

ECM <M/T>
OR
PCM <A/T>

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-13

STEP 11. Check the fan control module at ECM connector
C-49 <2.4L-M/T>, C-51 <3.0L-M/T>or PCM connector C-50
<2.4L-A/T>, C-52 <3.0L-A/T>.
(1) Disconnect ECM connector C-49 <2.4L-M/T>, C-51 <3.0L-

M/T> or PCM connector C-50 <2.4L-A/T>, C-52 <3.0L-A/
T>.

(2) Pull out pin 21 <2.4L-M/T> or 18 <2.4L-A/T, 3.0L> to

disconnect it.

(3) Reconnect ECM connector C-49 <2.4L-M/T>, C-51 <3.0L-

M/T> or PCM connector C-50 <2.4L-A/T>, C-52 <3.0L-A/T>
with pin 21 <2.4L-M/T> or 18 <2.4L-A/T, 3.0L> still
removed.

(4) Turn the ignition switch to "ON" position.

Q: Do the radiator fan motor and condenser fan motor

operate?
YES : Replace the ECM <M/T> or PCM <A/T>. Then go to

Step 12.

NO : Replace the radiator fan motor and fan control module

assembly.Then go to Step 12.

STEP 12. Check the symptoms.

Q: Do the radiator fan and condenser fan operate

correctly?
YES : This diagnosis is complete.
NO : Return to Step 1.

INSPECTION PROCEDURE 4: Radiator Fan and Condenser Fan do not Change Speed or Stop

NOTE: if the engine coolant temperature reaches 110

C (230

F) or higher, the radiator fan control rotates the

radiator fan for up to 5 minutes even after the ignition switch is turned to the "LOCK (OFF)" position [the fan
stops its rotation when the engine coolant temperature decreases to 110

C (230

F) or lower.]

Radiator Fan and Condenser Fan Drive Circuit
Refer to

P.14-6

CIRCUIT OPERATION

•

The fan controller is powered from fusible link
number 5.

•

The ECM <M/T> or PCM <A/T> judges the
required revolution speed of radiator fan motor
and condenser fan motor using the input signals
transmitted from A/C switch, automatic
compressor controller, vehicle speed sensor and
engine coolant temperature sensor. The ECM
<M/T> or PCM <A/T> activates the fan controller
to drive the radiator fan motor and condenser fan
motor.

TECHNICAL DESCRIPTION
The fan controller has variable control of the radiator
fan motor and the condenser fan motor speeds using
signals transmitted from the ECM <M/T> or PCM <A/
T>.

TROUBLESHOOTING HINTS

•

Malfunction of fan control relay

•

Malfunction of fan controller

•

Malfunction of ECM <M/T> or PCM <A/T>

DIAGNOSIS

Required Special Tool:
MB991223: Harness Set

AC000257

<2.4L-M/T>

<2.4L-A/T, 3.0L>

CONNECTOR C-49

CONNECTOR C-50, C-51, C-52

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-14

STEP 1. Check the fan control relay.
Refer to

P.14-18

Q: Is the fan control relay in good condition?

YES : Go to Step 2.
NO : Replace the part, then go to Step 6.

STEP 2. Check the harness wire between fan control relay
connector A-13X and fan controller connector A-30.
Q: Are the harness wire between fan control relay

connector A-13X and fan controller connector A-30
damaged?
YES : Repair or replace the part, then go to Step 6.
NO : Go to Step 3.

STEP 3. Check the circuit at ECM connector C-49 <2.4L-M/
T>, C-51 <3.0L-M/T>or PCM connector C-50 <2.4L-A/T>, C-
52 <3.0L-A/T>.
(1) Connect ECM connector C-49 <2.4L-M/T>, C-51 <3.0L-M/

T> or PCM connector C-50 <2.4L-A/T>, C-52 <3.0L-A/T>.

(2) Start the engine and run it at idle. [Engine coolant

temperature: 80

C (176

F) or less]

(3) Measure the voltage between terminal number 21 <2.4L-M/

T> or 18 <2.4L-A/T, 3.0L> and ground.

Q: Is the voltage 0

−

0.3 volt when radiator fan is not

operating?
YES : Go to Step 6.
NO : Go to Step 4.

AC000248AB

CONNECTOR: A-13X

BATTERY

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

AC000257

<2.4L-M/T>

<2.4L-A/T, 3.0L>

CONNECTOR C-49

CONNECTOR C-50, C-51, C-52

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