Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSMERCURY2009MILAN PREMIER, 3.0 1, AWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (EXCEPT DIESEL & HYBRID)DTC DIAGNOSISDTC P1479: - HIGH FAN CONTROL PRIMARY CIRCUIT
2009 Mercury Milan Premier, 3.0 1, AWD
DTC P1479: - High Fan Control Primary Circuit
2009 Mercury Milan Premier, 3.0 1, AWDSECTION DTC P1479: - High Fan Control Primary Circuit
DTC P1479: - HIGH FAN CONTROL PRIMARY CIRCUIT
| Description: | Monitors the High Fan Control (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: |
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| Diagnostic Aids: | When the HFCF PID reads YES, a concern 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 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. |
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| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to Pinpoint Test KF . | ||
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.