Mitsubishi Eclipse. Manual — part 652

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-11

STEP 7. Check the circuit at fan controller connector A-30
(terminal number 1).
(1) Disconnect fan controller connector A-30 (terminal number

1), and measure at the harness side connector.

(2) Measure the resistance between terminal number 1 and

ground.

Q: Is the resistance less than 2 ohm?

YES : Go to Step 9.
NO : Go to Step 8.

STEP 8. Check the harness wire between fan controller
connector A-30 (terminal number 1) and ground.
Q: Are the harness wires between fan controller connector

A-30 (terminal number 1) and ground damaged?
YES : Repair or replace them, then go to Step 12.
NO : Go to Step 9.

AC000252 AB

CONNECTOR: A-30

AC000270 AB

CONNECTOR: A-30

RADIATOR
FAN

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-12

STEP 9. Check the circuit at ECM connector C-49 (terminal
number 21) <2.4L-M/T>, C-51 (terminal number 18)
<3.0L-M/T>or PCM connector C-50 (terminal number 18)
<2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>.
(1) Connect ECM connector C-49 (terminal number 21)

<2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or
PCM connector C-50 (terminal number 18) <2.4L-A/T>,
C-52 (terminal number 18) <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.

STEP 10. Check the harness wire between ECM connector
C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal
number 18) <3.0L-M/T> or PCM connector C-50 (terminal
number 18) <2.4L-A/T>, C-52 (terminal number 18)
<3.0L-A/T> and fan controller connector A-30 (terminal
number 2).

NOTE: If intermediate connector C-07 (terminal number 6) is
damaged, repair or replace it. Refer to GROUP 00E, Harness
Connector Inspection

P.00E-2

.

AC000254

CONNECTOR C-49

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

<2.4L-M/T>

<2.4L-A/T, 3.0L>

AC

AC000244

CONNECTOR: C-07

AC

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-13

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

(terminal number 21) <2.4L-M/T>, C-51 (terminal number
18) <3.0L-M/T> or PCM connector C-50 (terminal number
18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>
and fan controller connector A-30 (terminal number 2)
damaged?
YES : Repair or replace them, then go to Step 12.
NO : Go to Step 11.

STEP 11. Check the fan control module at ECM connector
C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal
number 18) <3.0L-M/T> or PCM connector C-50 (terminal
number 18) <2.4L-A/T>, C-52 (terminal number 18)
<3.0L-A/T>.
(1) Disconnect ECM connector C-49 (terminal number 21)

<2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or
PCM connector C-50 (terminal number 18) <2.4L-A/T>,
C-52 (terminal number 18) <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 (terminal number 21)

<2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or
PCM connector C-50 (terminal number 18) <2.4L-A/T>,
C-52 (terminal number 18) <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.

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

AC000257

<2.4L-M/T>

<2.4L-A/T, 3.0L>

CONNECTOR C-49

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

AC

ENGINE COOLING DIAGNOSIS

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COOLING SYSTEM

14-14

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 runs 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 110C (230F) 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 2.

• 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 compres-
sor 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

STEP 1. Check the fan control relay.
Refer to

P.14-20

.

Q: Is the fan control relay in good condition?

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