DTC P1477: - Additional Fan Relay Circuit
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2009 Mercury Mountaineer, 2009 Mercury Milan, 2009 Mercury Mariner, 2009 Mercury Grand Marquis, and 2009 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1477: - ADDITIONAL FAN RELAY CIRCUIT
| Description: | Monitors the Medium Fan Control (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 concern is currently 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 scan 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 |
| All | GO to Pinpoint Test KF . | ||