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

2005 Ford Econoline E150, Van Cargo, 5.4 LSECTION DTC P1479: High Fan Control (HFC)/Fan Control 3 (FC3) Primary Circuit Malfunction
P1479 - HIGH FAN CONTROL (HFC)/FAN CONTROL 3 (FC3) PRIMARY CIRCUIT MALFUNCTION

Description:  Monitors the HFC primary circuit output from the powertrain control module (PCM). The test fails if 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
Diagnostic Aids:  When the HFCF PID reads YES, a fault is present.
An open circuit or short to ground can only be detected when the PCM is not grounding the HFC circuit.
A short to voltage can only be detected when the PCM is grounding the HFC circuit.
During the key on engine off (KOEO) and key on engine running (KOER) self-test, the HFC circuit is cycled on and off.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
Taurus, Sable, Escape 3.0L, Mariner 3.0L, Ford GT GO to KF: Fan Control (FC) Relays STEP KF34. GO to KF: Fan Control (FC) Relays STEP KF34. GO to KF: Fan Control (FC) Relays STEP KF53.
All others GO to KF: Fan Control (FC) Relays STEP KF11. GO to KF: Fan Control (FC) Relays STEP KF11. GO to KF: Fan Control (FC) Relays STEP KF45.
RENDER: 1.0x

NO RELATED

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