AutoCodes – Ford – P1477 1999 Ford F150

P1477 1999 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 1999 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 1,738

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 1999 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 1999 Ford F150 - Medium Cooling Fan Control Primary Circuit Failure - AutoCodes.com — P1477 1999 Ford F150 Code - Medium Cooling Fan Control Primary Circuit Failure

What does this mean?

What are the Possible Causes of the DTC P1477 1999 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 1999 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 1999 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 1999 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 1999 Ford F150 Code

1. What are the common symptoms of OBDII code P1477 in a 1999 Ford F150?

- Common symptoms include the cooling fan not working properly, engine overheating, and the Check Engine light being illuminated.

2. What does the OBDII code P1477 for a 1999 Ford F150 indicate?

- This code indicates a Medium Cooling Fan Control Primary Circuit Failure, meaning there is an issue with the primary circuit controlling the medium-speed cooling fan.

3. What are the possible causes of OBDII code P1477 in a 1999 Ford F150?

- Possible causes include a faulty cooling fan relay, damaged wiring or connectors, a defective cooling fan motor, or issues with the cooling fan control module.

4. How can I diagnose the source of OBDII code P1477 in my 1999 Ford F150?

- To diagnose this code, you can start by checking the cooling fan relay, inspecting the wiring and connectors for any damage, testing the cooling fan motor, and verifying the operation of the cooling fan control module.

5. Can I continue driving my 1999 Ford F150 with OBDII code P1477 active?

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

6. How can I repair OBDII code P1477 in my 1999 Ford F150?

- Repairing this code typically involves replacing a faulty cooling fan relay, repairing any damaged wiring or connectors, replacing a defective cooling fan motor, or addressing issues with the cooling fan control module.

7. Will resetting the Check Engine light resolve OBDII code P1477 in my 1999 Ford F150?

- Resetting the Check Engine light may temporarily turn it off, but it will not fix the underlying issue causing the code. The root cause of the problem needs to be diagnosed and repaired.

8. Are there any DIY tips for troubleshooting OBDII code P1477 in a 1999 Ford F150?

- DIY tips include visually inspecting the cooling fan components, checking the fuse related to the cooling fan circuit, and using a multimeter to test for continuity in the wiring.

9. How much can I expect to pay to repair OBDII code P1477 in a 1999 Ford F150?

- The cost of repair can vary depending on the exact cause of the issue, but it may range from $100 to $400 for parts and labor.

10. Can a mechanic easily fix OBDII code P1477 in a 1999 Ford F150?

- A skilled mechanic with experience in automotive electrical systems should be able to diagnose and repair OBDII code P1477 in a 1999 Ford F150 efficiently.