Medium Cooling Fan Control Primary Circuit Failure
Table of contents
P1477 MERCURY Possible Causes
- Faulty Cooling Fan Relay
- Cooling Fan Relay harness is open or shorted
- Cooling Fan Relay circuit poor electrical connection
- Faulty Powertrain Control Module (PCM)
How do I fix code P1477 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P1477 MERCURY code
The cost of diagnosing the P1477 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1477 MERCURY Description
Monitors the medium fan control (MFC) primary circuit output from the Powertrain Control Module (PCM). The test fails if: With 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 coming through the medium speed FC relay coil to the MFC circuit).