Mitsubishi 3000GT Service Manual page 234

OPERATION
The engine control module controls the radiator fan motor and condenser fan motor according to
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the engine coolant temperature and vehicle speed via the power transistors (low speed side and
high speed side) in the module.
If the engine control unit turns ON the low speed side power transistor inside the module, the radiator
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fan motor relay (Lo) coil operates to send driving power supply (for low speed rotation) from the
battery to the radiator fan motor.
If the air conditioner compressor lock controller outputs the air conditioner compressor driving power
supply, the current flows to the condenser fan motor relay (Lo).
The condenser fan motor relay (Lo) will operate to send driving power supply (for low speed rotation)
from the battery to the condenser fan motor.
If the engine control module turns ON the high speed side power transistor inside the unit, the radiator
fan motor relay (Hi) and condenser fan motor relay (Hi) will operate to send the driving power supply
(for high speed rotation) to the radiator fan motor and condenser fan motor.
INSPECTION
Using Scan Tool
HARNESS INSPECTION
FAN MOTOR RELAY INSPECTION
Refer to Radiator Check in GROUP 14 and Power Relay Check in GROUP 55.
MULTIPORT On-Vehicle Inspection of MFI
FUEL INJECTION - Components
motor are driven at high speeds.
Measure input voltage applied to
ECM.
ECM connector: Discon-
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nected
Ignition switch: ON
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Battery voltage
TSB Revision
and condenser fan
motor rotate at high
STOP
Check the
fan motor
relay circuit