Engine-Codes - Ford - P1504 1999 FORD F150

P1504 1999 FORD F150 - Intake Air Control Circuit Malfunction

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

P1504 1999 FORD F150 Possible Causes

  • 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 is the P1504 1999 FORD F150 code repair?

Start by checking 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.

Tech Notes

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

What is the cost to diagnose the P1504 1999 FORD F150 code

Labor: 1.0

The cost to diagnose the P1504 1999 FORD F150 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
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When is the code detected?

Powertrain Control Module (PCM) has detected an electrical load failure on the Idle Air Control Valve (IACV) circuit.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1504 1999 FORD F150 Meaning

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.

More Information

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