DTC Advanced Diagnostics: P0480
DTC P0480:Radiator Fan Control (RFC) System Malfunction

General Description

The radiator fan control (RFC) unit cools the radiator and the A/C condenser by controlling the cooling fan motor. The powertrain control module (PCM) communicates with the RFC unit using the pulse-width modulation (PWM) signal. The PCM sends drive command to the RFC unit via the FAN CONTROL line using the PWM signal according to the condition of the vehicle. When a malfunction in the system is detected by self-diagnosis, the RFC unit makes FAN CONTROL line signal output to GND. When the PCM cannot receive the PWM signal via the FAN CONTROL line for a set time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
12 seconds or more
DTC Type
Two drive cycles, MIL off

Enable Conditions
Condition
Minimum
Maximum
Elapsed time after the PCM is activated
2 seconds
–
12 volt battery voltage [BATTERY]
10 V
18 V
Vehicle
ON mode
[ ]: HDS Parameter

Malfunction Threshold
The PCM cannot receive PWM signal from the RFC unit via the FAN CONTROL line for at least 12 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
RFC unit RFC DRIVER RLY OUT line open
RFC unit GND line open
RFC unit FAN CONTROL line open
RFC unit FAN CONTROL line short
RFC relay stuck off
RFC unit failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Turn the vehicle to the ON mode.

With the HDS
Select the RADIATOR FAN in the INSPECTION MENU with the HDS.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. The MIL does not come on.

Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.