DTC 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 MAIN_FAN_MOTOR 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 failure
Confirmation Procedure
Operating Condition
None.
With the HDS
Select the RADIATOR FAN in the Function Test 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.