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: |
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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 . | ||