AutoCodes – Ford – P1477 2002 Ford F150

P1477 2002 Ford F150 Code - Medium Cooling Fan Control Primary Circuit Failure

Quick Answer

Monitors the medium fan control (MFC) primary circuit output from the Powertrain Control Module (PCM). Common causes include Faulty Cooling Fan Relay, Cooling Fan Relay harness is open or shorted, Cooling Fan Relay circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1477 2002 Ford F150 indicates Medium Cooling Fan Control Primary Circuit Failure.
Common causes: Common causes include Faulty Cooling Fan Relay, Cooling Fan Relay harness is open or shorted, Cooling Fan Relay circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,143

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1477 2002 Ford F150 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).

OBDII Code P1477 2002 Ford F150 - Medium Cooling Fan Control Primary Circuit Failure - AutoCodes.com — P1477 2002 Ford F150 Code - Medium Cooling Fan Control Primary Circuit Failure

What does this mean?

What are the Possible Causes of the DTC P1477 2002 Ford F150?

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 to Fix the DTC P1477 2002 Ford F150?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1477 2002 Ford F150 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1477 2002 Ford F150 code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1477 2002 Ford F150 Code

1. What are the common symptoms of OBDII code P1477 in a 2002 Ford F150?

- Common symptoms include the cooling fan running at high speed constantly, engine overheating, and the Check Engine Light being illuminated.

2. What could cause the OBDII code P1477 to appear in a 2002 Ford F150?

- The code P1477 usually indicates a fault in the primary circuit of the cooling fan control system, which could be caused by a faulty cooling fan relay, wiring issues, or a malfunctioning cooling fan motor.

3. How can I diagnose the OBDII code P1477 in my 2002 Ford F150?

- Diagnosis typically involves checking the cooling fan relay, inspecting the wiring for any damage or loose connections, and testing the cooling fan motor for proper operation.

4. Can I still drive my Ford F150 with the OBDII code P1477 present?

- It is not recommended to drive your vehicle with the code P1477 present, as it can lead to engine overheating and potential damage. It is best to address the issue promptly.

5. How can I repair the OBDII code P1477 in my 2002 Ford F150?

- Repairing the code P1477 may involve replacing the cooling fan relay, repairing any damaged wiring, or replacing the cooling fan motor if necessary.

6. Is it possible to reset the OBDII code P1477 in a 2002 Ford F150 without fixing the underlying issue?

- While you can clear the code using an OBDII scanner, it is not recommended to do so without addressing the root cause, as the issue may persist and lead to further problems.

7. Are there any DIY tips for fixing the OBDII code P1477 in a 2002 Ford F150?

- DIY tips may include visually inspecting the cooling fan relay and wiring for any obvious issues, checking the fuse related to the cooling fan, and testing the cooling fan motor for functionality.

8. Can a faulty thermostat cause the OBDII code P1477 to appear in a 2002 Ford F150?

- While a faulty thermostat can contribute to engine overheating, it is not directly related to the P1477 code, which specifically points to issues with the cooling fan control circuit.

9. How long does it typically take to repair the OBDII code P1477 in a 2002 Ford F150?

- The repair time can vary depending on the exact cause of the issue, but it may take anywhere from 1-3 hours to diagnose and fix the problem.

10. Is it necessary to take my 2002 Ford F150 to a mechanic for the OBDII code P1477 repair?

- While some DIY enthusiasts may be able to address the issue themselves, it is recommended to consult a qualified mechanic for proper diagnosis and repair of the P1477 code to ensure it is resolved correctly.