DTC P1477: Medium Fan Control (MFC) Primary Circuit Failure
WARNING: This page is about a different variant/trim than selected.
P1477 - MEDIUM FAN CONTROL (MFC) PRIMARY CIRCUIT FAILURE
| Description: | Monitors the MFC primary circuit output from the powertrain control module (PCM). The test fails if the MFC output commanded on (grounded), excessive current draw is detected on the MFC circuit or, with the MFC circuit commanded off, voltage is not detected on the MFC circuit (the PCM expects to detect IGN START/RUN voltage through the medium speed FC relay coil to the MFC circuit). | ||
| Possible Causes: |
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| Diagnostic Aids: | When the MFCF 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 MFC circuit. A short to voltage can only be detected when the PCM is grounding the MFC circuit. During the key on engine off (KOEO) and key on engine running (KOER) self-test, the MFC circuit is cycled on and off. When using output test mode on a diagnostic tool, and commanding the low speed fan on, the PCM also activates the medium speed fan output. |
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| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| Freestar/Monterey, Focus | GO to KF: Fan Control (FC) Relays STEP KF25. | GO to KF: Fan Control (FC) Relays STEP KF25. | GO to KF: Fan Control (FC) Relays STEP KF51. |
| All others | GO to KF: Fan Control (FC) Relays STEP KF6. | GO to KF: Fan Control (FC) Relays STEP KF6. | GO to KF: Fan Control (FC) Relays STEP KF47. |