AutoCodes – Acura – P0511 Acura

P0511 Acura Code - Idle Control System Malfunction

Quick Answer

This system automatically controls engine idle speed to a specified level. Common causes include Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve harness is open or shorted, Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve circuit poor electrical connection, Faulty Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve. 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: P0511 Acura indicates Idle Control System Malfunction.
Common causes: Common causes include Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve harness is open or shorted, Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve circuit poor electrical connection, Faulty Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve.
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 4,272

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

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Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
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Code P0511 Acura Description

This system automatically controls engine idle speed to a specified level. Idle speed is controlled through fine adjustment of the amount of air which by-passes the throttle valve via Idle Air Control Valve (IACV) and Auxiliary Air Control (AAC) Valve. The IACV-AAC valve changes the opening of the air by-pass passage to control the amount of auxiliary air. This valve is actuated by a step motor built into the valve, which moves the valve in the axial direction in steps corresponding to the Engine Control Module (ECM) output signals.
One step of IACV-AAC valve movement causes the respective opening of the air by-pass passage. (i.e. when the step advances, the opening is enlarged.) The opening of the valve is varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects the actual engine speed and sends a signal to the ECM. The ECM then controls the step position of the IACV-AAC valve so that engine speed coincides with the target value memorized in ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by takig into consideration various engine conditions, such as during warm up, deceleration, and engine load (air conditioner, power steering and cooling fan operation).

OBDII Code P0511 Acura - Idle Control System Malfunction - AutoCodes.com — P0511 Acura Code - Idle Control System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0511 Acura?

Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve harness is open or shorted
Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve circuit poor electrical connection
Faulty Idle Air Control Valve (IACV)/Auxiliary Air Control (AAC) Valve

How to Fix the DTC P0511 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 P0511 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.

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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.