The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
COOLING FAN MOTOR
The cooling fan operates at each speed when the current flows in the cooling fan motor as per the following.
The cooling fan operates at low (LOW) speed when cooling fan motors-1 and -2 are circuited in series under the middle speed condition. Refer to See: Description and Operation\System Diagram.
COOLING FAN
Diagnosis Procedure
1.CHECK COOLING FAN RELAY POWER SUPPLY CIRCUIT
Turn ignition switch OFF.
Disconnect cooling fan relays-2, -3.
Turn ignition switch ON.
Check the voltage between cooling fan relays-2, -3 harness connectors and ground.
Is the Inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2. 2.DETECT MALFUNCTIONING PART
Check the following.
10 A fuse (No. 33)
40 A fusible link (letter K)
IPDM E/R harness connector E18
Harness for open or short between cooling fan relay-2 and battery
Harness for open or short between cooling fan relay-3 and battery
Harness for open or short between cooling fan relay-2 and IPDM E/R
Harness for open or short between cooling fan relay-3 and IPDM E/R >> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK COOLING FAN RELAY OUTPUT SIGNAL CIRCUIT
Turn ignition switch OFF.
Disconnect IPDM E/R harness connectors.
Check the continuity between cooling fan relay-2, -3 harness connectors and IPDM E/R harness connector.
Also check harness for short to ground and short to power. Is the Inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4. 4.DETECT MALFUNCTIONING PART
Check the following.
Harness for open or short between cooling fan relay-2 and IPDM E/R
Harness for open or short between cooling fan relay-3 and IPDM E/R >> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK COOLING FAN MOTOR POWER SUPPLY CIRCUIT
Disconnect cooling fan motor-1 harness connector.
Check the voltage between cooling fan motor-1 harness connector and ground.
Is the Inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6. 6.DETECT MALFUNCTIONING PART
Check the following.
40 A fusible link (letter M)
Harness connector E12, E203
Harness for open or short between cooling fan motor-1 and battery >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK COOLING FAN MOTOR CIRCUIT-I
Disconnect cooling fan motor-2 harness connector.
Check the continuity between cooling fan relay-2, -3 harness connectors and cooling fan motor-1, -2 harness connectors.
Also check harness for short to ground and short to power. Is the Inspection result normal?
YES >> GO TO 9.
NO >> GO TO 8. 8.DETECT MALFUNCTIONING PART
Check the following.
Harness connector E12, E203
Harness for open or short between cooling fan motor-1 and cooling fan relay-2
Harness for open or short between cooling fan motor-1 and cooling fan relay-3
Harness for open or short between cooling fan motor-2 and cooling fan relay-2
Harness for open or short between cooling fan motor-2 and cooling fan relay-3 >> Repair open circuit, short to ground or short to power in harness or connectors.
9.CHECK COOLING FAN MOTOR CIRCUIT-II
Check the continuity between IPDM E/R harness connector and cooling fan motor-1, -2 harness connector.
Also check harness for short to ground and short to power. Is the Inspection result normal?
YES >> GO TO 11.
NO >> GO TO 10. 10.DETECT MALFUNCTIONING PART
Check the following.
Harness connector E70, E305
Harness for open or short between cooling fan motor-1 and IPDM E/R
Harness for open or short between cooling fan motor-2 and IPDM E/R >> Repair open circuit, short to ground or short to power in harness or connectors.
11.CHECK COOLING FAN MOTOR CIRCUIT-III
Check the continuity between cooling fan relay-2, -3 harness connectors and ground.
Also check harness for short to ground and short to power. Is the Inspection result normal?
YES >> GO TO 12.
NO >> Repair open circuit, short to ground or short to power in harness or connectors. 12.CHECK COOLING FAN MOTOR CIRCUIT-IV
Check the continuity between cooling fan motor-2 harness connector and ground.
Also check harness for short to ground and short to power. Is the Inspection result normal?