DTC P0480: Fan 1 Control Circuit: Notes
1. -
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
The radiator fan keeps rotating.
Wiring diagram:
Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .
Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .
After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .
- CHECK HARNESS OF RADIATOR MAIN FAN DIAGNOSTIC SIGNAL (OPEN)
.
- Turn the ignition switch to OFF.
- Disconnect the connector from ECM.
- Disconnect the connector from the main fan motor.
- Disconnect the connector from radiator fan control module (main).
- Measure the resistance in harness between ECM connector and main fan motor connector, and between ECM connector and radiator fan control module (main) connector.
Connector and terminal
(B61) No. 18 - (Fr51) No. 1:
(B61) No. 18 - (Fr32) No. 2:
Is the resistance less than 1 Ω?
Yes: Go to 2 .
No: Repair the following item.
- Open circuit in harness between ECM connector and main fan motor connector
- Open circuit in harness between ECM connector and radiator fan control module (main) connector
- Poor contact of ECM connector
- Poor contact of main fan motor connector
- Poor contact of radiator fan control module (main) connector
- Poor contact of coupling connector no yes no
- CHECK HARNESS OF MAIN FAN MOTOR DIAGNOSTIC SIGNAL (SHORT TO POWER SUPPLY)
.
- Turn the ignition switch to ON.
- Measure the voltage of harness between ECM connector and engine ground.
Connector and terminal
(B61) No. 18 (+) - Engine ground (-):
Is the voltage less than 1 V?
Yes: Go to 3 .
No: Repair the following item.
- Short circuit to power supply in harness between ECM connector and main fan motor connector
- Short circuit to power supply in harness between ECM connector and radiator fan control module (main) connector
- CHECK HARNESS BETWEEN RADIATOR FAN CONTROL MODULE (MAIN) AND MAIN FAN MOTOR (MOTOR DOWNSTREAM) (OPEN)
.
- Turn the ignition switch to OFF.
- Measure the resistance of harness between radiator fan control module (main) connector and main fan motor connector.
Connector and terminal
(Fr32) No. 1 - (Fr51) No. 2:
Is the resistance less than 1 Ω?
Yes: Go to 4 .
No: Repair the following item.
- Open circuit in harness between radiator fan control module (main) connector and main fan motor connector
- Poor contact of radiator fan control module (main) connector
- Poor contact of main fan motor connector
- Poor contact of coupling connector
- CHECK HARNESS BETWEEN RADIATOR FAN CONTROL MODULE (MAIN) AND MAIN FAN MOTOR (MOTOR DOWNSTREAM) (SHORT TO POWER SUPPLY)
.
- Turn the ignition switch to ON.
- Measure the voltage of harness between radiator fan control module (main) connector and engine ground.
Connector and terminal
(Fr32) No. 1 (+) - Engine ground (-):
Is the voltage less than 1 V?
Yes: Go to 5 .
No: Repair the short circuit to power supply in harness between radiator fan control module (main) connector and main fan motor connector.
- CHECK HARNESS BETWEEN RADIATOR FAN CONTROL MODULE (MAIN) AND CHASSIS GROUND (OPEN)
.
- Turn the ignition switch to OFF.
- Measure the resistance of harness between radiator fan control module (main) connector and engine ground.
Connector and terminal
(Fr31) No. 1 - Engine ground:
Is the resistance less than 1 Ω?
Yes: Go to 6 .
No: Repair the following item.
- Open circuit in harness between radiator fan control module (main) connector and engine ground
- Poor contact of radiator fan control module (main) connector
- Poor contact of engine ground
- Poor contact of coupling connector
- Poor contact of joint connector
- CHECK HARNESS OF MAIN FAN MOTOR DRIVE SIGNAL CIRCUIT (SHORT TO POWER SUPPLY)
.
- Turn the ignition switch to ON.
- Measure the voltage of harness between ECM connector and engine ground.
Connector and terminal
(B61) No. 23 (+) - Engine ground (-):
Is the voltage less than 1 V?
Yes: Replace the radiator fan control module (main). Ref. to COOLING (H4DOTC)>RADIATOR FAN AND FAN MOTOR ASSEMBLY .
No: Repair the short circuit to power supply in harness between ECM connector and radiator fan control module (main) connector.