DTC P0481: High Fan Control (HFC) Primary Circuit Failure
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
P0481 - HIGH FAN CONTROL (HFC) PRIMARY CIRCUIT FAILURE
| 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: |
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| 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. |
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| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to Pinpoint Test KF . | ||