AutoCodes – Honda – P0505 1996 Honda Civic

P0505 1996 Honda Civic Code - Idle Air Control Valve

Quick Answer

This system automatically controls engine idle speed to a specified level. Common causes include Faulty Idle Air Control Valve (IACV) valve, IAC valve harness is open or shorted, IAC 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: P0505 1996 Honda Civic indicates Idle Air Control Valve.
Common causes: Common causes include Faulty Idle Air Control Valve (IACV) valve, IAC valve harness is open or shorted, IAC 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 11,038

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 May 18, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code P0505 1996 Honda Civic 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 taking into consideration various engine conditions, such as during warm-up, deceleration, and engine load (air conditioner, power steering, and cooling fan operation).

OBDII Code P0505 1996 Honda Civic - Idle Air Control Valve - AutoCodes.com — P0505 1996 Honda Civic Code - Idle Air Control Valve

What does this mean?

What are the Possible Causes of the DTC P0505 1996 Honda Civic?

Faulty Idle Air Control Valve (IACV) valve
IAC valve harness is open or shorted
IAC valve circuit poor electrical connection

How to Fix the DTC P0505 1996 Honda Civic?

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 problem is very common with Honda Civic, you can clean the idle air control valve and adjusting the engine idle speed (disconnect the battery and touch the two terminals together for an hour or so which will clear the ECM, connect the terminals back and start the car and let it idle of 15min without touching anything this usually takes care of the problem).

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0505 1996 Honda Civic 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 P0505 1996 Honda Civic Code

1. What does OBDII code P0505 mean on a 1996 Honda Civic?

Code P0505 on a 1996 Honda Civic indicates a malfunction in the idle air control system.

2. What are the common symptoms of a P0505 code in a 1996 Honda Civic?

Common symptoms of a P0505 code include erratic idle speed, stalling at idle, and poor acceleration.

3. What can cause the P0505 code to appear on a 1996 Honda Civic?

The most common cause of a P0505 code in a 1996 Honda Civic is a faulty idle air control valve (IACV).

4. How can I diagnose the cause of a P0505 code on my 1996 Honda Civic?

To diagnose a P0505 code, you can perform a visual inspection of the IACV, check for vacuum leaks, and test the IACV with a multimeter.

5. Can a dirty throttle body cause a P0505 code on a 1996 Honda Civic?

Yes, a dirty throttle body can restrict airflow and cause irregular idle, potentially triggering a P0505 code.

6. How can I fix a P0505 code on my 1996 Honda Civic?

To fix a P0505 code, you may need to clean or replace the idle air control valve, check and clean the throttle body, and ensure there are no vacuum leaks.

7. Is it safe to continue driving with a P0505 code on a 1996 Honda Civic?

While the car may still be driveable with a P0505 code, it is recommended to address the issue promptly to prevent further damage to the engine.

8. Can a P0505 code on a 1996 Honda Civic affect fuel economy?

Yes, a P0505 code can lead to poor fuel economy due to irregular idling and improper air-fuel mixture.

9. Will resetting the OBDII system clear a P0505 code on a 1996 Honda Civic?

Resetting the OBDII system may temporarily clear the P0505 code, but if the underlying issue is not fixed, the code is likely to reappear.

10. How much does it typically cost to repair a P0505 code on a 1996 Honda Civic?

The cost of repairing a P0505 code on a 1996 Honda Civic can vary depending on the exact cause, but it may range from $100 to $300 for parts and labor.