P1479 - High Fan Control (HFC)/Fan Control 3 (FC3) Primary Circuit Malfunction

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

P1479 - HIGH FAN CONTROL (HFC)/FAN CONTROL 3 (FC3) PRIMARY CIRCUIT MALFUNCTION

Description:	Monitors the high fan control (HFC) primary circuit output from the PCM. The test fails if: With the HFC output commanded on (grounded), excessive current draw is detected on the HFC circuit; or, with the HFC circuit commanded off, voltage is not detected on the HFC circuit (the PCM expects to detect VPWR voltage through the high speed FC relay coil to the HFC circuit).
Possible Causes:	Open or shorted HFC circuit. Open VPWR circuit to the high speed FC relay. Damaged high speed FC relay (or CCRM). Damaged PCM.
Diagnostic Aids:	When the HFCF PID reads YES, a fault is currently present. An open circuit or short to ground can only be detected when the PCM is not grounding the HFC circuit. A short to power can only be detected when the PCM is grounding the HFC circuit. During the KOEO and KOER self-test, the HFC circuit is cycled on and off.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
Mustang	GO to X: Constant Control Relay Module (CCRM) STEP 4	GO to X: Constant Control Relay Module (CCRM) STEP 4	GO to X: Constant Control Relay Module (CCRM) STEP 19
Taurus, Sable, Focus 2.0L, Escape 3.0L	GO to KF: Fan Control relays STEP 34	GO to KF: Fan Control relays STEP 34	GO to KF: Fan Control relays STEP 53
All Others	GO to KF: Fan Control relays STEP 11	GO to KF: Fan Control relays STEP 11	GO to KF: Fan Control relays STEP 45