Radiator Fan Control Relay System - Mitsubishi Lancer Evolution-VII Workshop Manual

Inspection Procedure 24

Radiator fan control relay system

When the engine control relay turns ON, the radiator fan control relay turns ON
simultaneously, and power is supplied to the fan controller.
The radiator fan motor is driven when the fan motor drive signal is input to the
fan controller from the engine-ECU.
Check the following connector: A-09X
OK
D Check the radiator fan control relay. (Refer to GROUP 14
- On-vehicle Service.)
OK
Measure at the A-09X radiator fan
control relay connector.
D Remove the relay, and measure
at the connector side.
(1) Resistance between terminal No.
3 and earth
OK: 2 Ω or less
(2) Voltage between terminal No. 1
and earth
(Ignition switch: ON)
OK: System voltage
(3) Voltage between terminal No. 4
and earth
OK: System voltage
OK
Check the following connector: A-21
OK
Measure at the A-21 fan controller
connector.
D Disconnect the connector to
measure at the harness side.
D Ignition switch: ON
D Voltage between terminal No. 3
and earth
OK: System voltage
OK
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MPI -
Troubleshooting
NG
NG
(1) NG
Check and repair the harness
between the radiator fan control relay
and body earth.
D Check for disconnection and
damage of the earth cable.
(2) NG
Check the following connectors:
C-136 <R.H. drive vehicles>, A-13
<L.H. drive vehicles>, C-108, B-11X
Check and repair the harness
between the radiator fan control relay
and engine control relay.
D Check for disconnection and
short-circuit of the power cable.
(3) NG
Check and repair the harness
between the battery and radiator fan
control relay.
D Check for disconnection and
short-circuit of the power cable.
NG
Repair
NG
Check the harness between the
radiator fan control relay and fan
controller.
D Check for disconnection and
short-circuit of the output cable.
Check the following connectors:
C-136 <R.H. drive vehicles>, A-13
<L.H. drive vehicles>, C-108, B-11X
Check the harness between the
radiator fan control relay and engine
control relay.
D Check for damage of the power
cable.
Check and repair the harness
between the radiator fan control relay
and body earth.
D Check for damage of the earth
cable.
Probable cause
D Radiator fan control relay malfunction
D Fan controller malfunction
D Radiator fan motor malfunction
D Engine-ECU malfunction
Repair
Replace the radiator fan control relay.
NG
OK
NG
OK
OK
NG
OK
NG
OK
OK
13A-87
Repair
Repair
Repair
Repair