AutoCodes – Ford – P1504 2002 Ford F150

P1504 2002 Ford F150 Code - Intake Air Control Circuit Malfunction

Quick Answer

The Idle Air Control Valve (IACV) valve assembly controls the engine idle speed and provides a dashpot function. Common causes include Faulty Idle Air Control Valve, Idle Air Control Valve harness is open or shorted, Idle Air Control Valve 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: P1504 2002 Ford F150 indicates Intake Air Control Circuit Malfunction.
Common causes: Common causes include Faulty Idle Air Control Valve, Idle Air Control Valve harness is open or shorted, Idle Air Control Valve 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 7,049

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 25, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P1504 2002 Ford F150 Description

The Idle Air Control Valve (IACV) valve assembly controls the engine idle speed and provides a dashpot function. The IAC valve assembly meters intake air around the throttle plate through a bypass within the IAC valve assembly and throttle body. The Powertrain Control Module (PCM) determines the desired idle speed or bypass air and signals the IAC valve assembly through a specified duty cycle. The IAC valve responds by positioning the IAC valve to control the amount of bypassed air. The PCM monitors engine RPM and increases or decreases the IAC duty cycle in order to achieve the desired RPM.

OBDII Code P1504 2002 Ford F150 - Intake Air Control Circuit Malfunction - AutoCodes.com — P1504 2002 Ford F150 Code - Intake Air Control Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P1504 2002 Ford F150?

Faulty Idle Air Control Valve
Idle Air Control Valve harness is open or shorted
Idle Air Control Valve circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P1504 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 does this mean?

Code Tech Notes

The Idle Air Control solenoid resistance is from 6 to 13 ohms.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1504 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.

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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 P1504 2002 Ford F150 Code

1. What does the OBDII code P1504 indicate on a 2002 Ford F150?

The P1504 code on a 2002 Ford F150 indicates an "Intake Air Control Circuit Malfunction," specifically pointing to a fault in the Idle Air Control (IAC) system's electrical circuit.

2. What are common symptoms of code P1504 in a 2002 Ford F150?

Symptoms include erratic or high idle, engine stalling at idle, engine stalling when coming to a stop, and sometimes the engine may idle too low or fluctuate.

3. What can cause the P1504 code to appear on a 2002 Ford F150?

Common causes include a faulty Idle Air Control (IAC) valve, damaged wiring or connectors in the IAC circuit, or a poor electrical connection at the IAC valve.

4. How can I troubleshoot the P1504 code in my 2002 Ford F150?

Start by inspecting the IAC valve and its wiring for any visible damage. Check the electrical connections for corrosion, looseness, or damage. Use a multimeter to verify the integrity of the wiring from the IAC valve to the ECM.

5. Can a dirty IAC valve cause the P1504 code on a 2002 Ford F150?

Yes, a dirty or clogged IAC valve can lead to improper air flow, triggering the P1504 code. Cleaning the IAC valve with appropriate cleaner can sometimes resolve this issue.

6. What are the steps to replace the IAC valve on a 2002 Ford F150 if it's causing the P1504 code?

To replace the IAC valve, disconnect the battery, remove the electrical connector and mounting screws from the IAC valve, then remove the valve. Install the new valve, re-attach the screws and connector, and reconnect the battery.

7. How important is it to address the P1504 code in a 2002 Ford F150?

It is important to address the P1504 code promptly as it can affect the drivability of your vehicle and potentially lead to the engine stalling, which can be dangerous in traffic.

8. Will a regular engine scan tool detect the P1504 code on a 2002 Ford F150?

Yes, a standard OBDII scanner will detect the P1504 code and any other codes that may be stored in the vehicleâ€™s computer system.

9. Can the P1504 code affect the fuel economy of my 2002 Ford F150?

Yes, since the P1504 code involves a malfunction in the air intake control, it can lead to an improper air-fuel mixture, thereby reducing the fuel efficiency of your vehicle.