AutoCodes – Ford – P1477 1997 Ford F150

P1477 1997 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 1997 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 1,932

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 1997 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 1997 Ford F150 - Medium Cooling Fan Control Primary Circuit Failure - AutoCodes.com — P1477 1997 Ford F150 Code - Medium Cooling Fan Control Primary Circuit Failure

What does this mean?

What are the Possible Causes of the DTC P1477 1997 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 1997 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 1997 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 1997 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 1997 Ford F150 Code

1. What are the common symptoms of OBDII code P1477 in a 1997 Ford F150?

- Common symptoms include overheating of the engine, erratic cooling fan operation, and the Check Engine light coming on.

2. What can cause the OBDII code P1477 to trigger in a 1997 Ford F150?

- The primary causes of this code are a faulty cooling fan control module, a malfunctioning cooling fan relay, or issues with the wiring or connectors in the cooling fan circuit.

3. How can I diagnose the OBDII code P1477 in my 1997 Ford F150?

- A diagnostic scan tool can help identify the specific issue by reading the code and providing data related to the cooling fan control circuit.

4. Is it safe to drive my 1997 Ford F150 with the OBDII code P1477 active?

- It is not recommended to drive with this code active, as it may lead to engine overheating and potential damage. It's best to address the issue promptly.

5. Can I reset the OBDII code P1477 in my 1997 Ford F150 by disconnecting the battery?

- Disconnecting the battery may clear the code temporarily, but it will likely return if the underlying issue is not resolved. It's best to diagnose and repair the root cause.

6. How can I repair the OBDII code P1477 in my 1997 Ford F150?

- Repair options include replacing the cooling fan control module, testing and replacing the cooling fan relay, and checking for any damaged wiring or connectors in the circuit.

7. Are there any DIY tips for fixing the OBDII code P1477 in a 1997 Ford F150?

- DIY tips include checking the cooling fan fuse, inspecting the wiring for damage, and ensuring the cooling fan operates properly when commanded.

8. Will fixing the OBDII code P1477 in my 1997 Ford F150 improve fuel efficiency?

- Addressing this code may indirectly improve fuel efficiency by ensuring the engine operates at optimal temperatures and does not overheat.

9. How much does it typically cost to repair the OBDII code P1477 in a 1997 Ford F150?

- The cost of repair can vary depending on the specific issue, but it may range from $100 to $500, including parts and labor.

10. Can the OBDII code P1477 in a 1997 Ford F150 cause long-term engine damage if left unresolved?

- Yes, if left unresolved, the code can lead to engine overheating, which may cause severe damage over time. It's important to address this issue promptly.