Engine-CodesLincoln – P1506 Lincoln

P1506 Lincoln Code - Idle Air Control Overspeed Error

Quick Answer

The P1506 OBD-II diagnostic trouble code for Lincoln vehicles indicates an Idle Air Control Overspeed Error. Common causes include Malfunctioning IAC valve: The idle air control valve may be stuck open or closed, causing overspeed, Vacuum leak: A vacuum leak in the intake system can disrupt the airflow and lead to idle speed issues, Dirty throttle body: A buildup of carbon deposits or debris in the throttle body can affect airflow and idle speed. 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
P1506 Lincoln indicates Idle Air Control Overspeed Error.
Common causes
Common causes include Malfunctioning IAC valve: The idle air control valve may be stuck open or closed, causing overspeed, Vacuum leak: A vacuum leak in the intake system can disrupt the airflow and lead to idle speed issues, Dirty throttle body: A buildup of carbon deposits or debris in the throttle body can affect airflow and idle speed.
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.
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code P1506 Lincoln Description

The P1506 OBD-II diagnostic trouble code for Lincoln vehicles indicates an Idle Air Control Overspeed Error. The Idle Air Control (IAC) valve is responsible for controlling the engine's idle speed by regulating the amount of air entering the engine. When the engine is idling, the IAC valve adjusts the airflow to maintain a stable idle speed. The P1506 code is triggered when the engine's idle speed exceeds the predetermined limit set by the vehicle's computer.

OBDII Code P1506 Lincoln - Idle Air Control Overspeed Error
P1506 Lincoln Code - Idle Air Control Overspeed Error

Common Causes of P1506 Lincoln

  1. Malfunctioning IAC valve: The idle air control valve may be stuck open or closed, causing overspeed.
  2. Vacuum leak: A vacuum leak in the intake system can disrupt the airflow and lead to idle speed issues.
  3. Dirty throttle body: A buildup of carbon deposits or debris in the throttle body can affect airflow and idle speed.
  4. Faulty throttle position sensor: The throttle position sensor may send incorrect signals to the engine control module, affecting idle speed control.
  5. Engine computer issues: Problems with the engine control module or software can lead to idle speed errors.

Symptoms of P1506 Lincoln

  1. Rough idle: The engine may idle erratically, with fluctuations in RPMs.
  2. Stalling: The engine may stall unexpectedly, especially when coming to a stop.
  3. Decreased fuel efficiency: The vehicle may consume more fuel than usual due to the improper idle speed.
  4. Surging: The engine may surge or exhibit sudden acceleration when idling.
  5. Check Engine Light: The Check Engine Light may illuminate on the dashboard to indicate a problem with the idle air control system.

How to Fix P1506 Lincoln

  1. Inspect the IAC valve: Check the idle air control valve for proper operation and clean or replace it if necessary.
  2. Check for vacuum leaks: Inspect the intake system for any leaks and repair or replace damaged hoses.
  3. Clean the throttle body: Remove any carbon buildup or debris from the throttle body to ensure smooth airflow.
  4. Test the throttle position sensor: Check the throttle position sensor for proper function and replace it if needed.
  5. Reset the engine computer: Clear the error code from the engine control module and reset the idle speed parameters.

Cost to Fix P1506 Lincoln

The cost of repairing the Idle Air Control Overspeed Error can vary depending on the specific cause of the issue and the labor rates in your area. On average, the parts for this repair may range from $50 to $200, while the labor costs can be between $100 and $300. Overall, the total repair cost could be anywhere from $150 to $500. It's recommended to consult with a professional mechanic to determine the exact cost for your Lincoln vehicle.

Tech Notes for P1506 Lincoln

The P1506 code means that the engine idle is out of factory specification. Sometimes the Idle Air Control (IAC) may have carbon built up. Disconnect the car battery, remove the valve, clean, re-install valve, and drive the vehicle for about 5 minutes with the headlights and A/C ON to get the idle relearned.

Also, check for intake leaks or stuck PCV Valve.

If the problem persistss, the IAC valve may need to be replaced.

When is the Code Detected?

The P1506 code sets when the Powertrain Control Module (PCM) detects an engine idle speed that is greater than the desired RPM.

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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 P1506 Lincoln Code

No Frequently Asked Questions about P1506 Lincoln Code found.

Discuss the causes and fixes for P1506 Lincoln OBDII Code

  • I get this on my 97 Lincoln Continental. It is the only code thrown. Engine idle is 817 RPM. I believe it has to do with car overheating issues while driving. Does not appear at idle. I have replaced Thermostat, water pump, serpentine belt, tension pulley, radiator. Dual electric fans work fine. A/C was removed (by passed). Car runs good. No misses. Starts up OK. Degas and cap OK.
    Have not yet done engine compression or engine leak down test.
    Do not yet have a remedy.