AutoCodes – Acura – P1509 Acura

P1509 Acura Code - Idle Air Control Valve System High RPM

Quick Answer

The target idle speed is in the Engine Control Module (ECM) memory for various engine conditions (coolant temperature, A/C operation and so on). 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: P1509 Acura indicates Idle Air Control Valve System High RPM.
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 3,253

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
Cost to Diagnose
Comments
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Code P1509 Acura Description

The target idle speed is in the Engine Control Module (ECM) memory for various engine conditions (coolant temperature, A/C operation and so on). The ECM keeps the actual idle speed at the target idle speed by switching the Idle Air Control Valve IACV) ON/OFF to control the intake airflow. If the IACV output duty cycle (the length of ON time) is out of a specified range, a malfunction is detected and a DTC is stored.

OBDII Code P1509 Acura - Idle Air Control Valve System High RPM - AutoCodes.com — P1509 Acura Code - Idle Air Control Valve System High RPM

What does this mean?

What are the Possible Causes of the DTC P1509 Acura?

Faulty Idle Air Control Valve
Idle Air Control Valve harness is open or shorted
Idle Air Control Valve circuit poor electrical connection

How to Fix the DTC P1509 Acura?

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 P1509 Acura 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 P1509 Acura 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.