The diagnostic trouble code P0509 indicates an issue with the Idle Air Control (IAC) system circuit being too high. The Idle Air Control system regulates the amount of air entering the engine while the vehicle is idling. The IAC valve adjusts the idle speed by controlling the amount of air flowing through the throttle body bypass passage.

When your OBD-II equipped vehicle exhibits a malfunction indicator lamp (MIL) and a stored code P0509, it means that the powertrain control module (PCM) has detected a problem with the intake idle air control (IAC) circuit, in this case a value that is higher than expected.

P0509 is a diagnostic trouble code (DTC) for "Idle Air Control System Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.

2024年5月5日 · P0509 Explained: This code indicates that your vehicle’s idle speed is higher than expected. Symptoms to Watch: High RPMs, stalling, rough idling, and increased fuel consumption. Common Causes: Issues can stem from a faulty IAC valve, vacuum leaks, or electrical problems.

To fix fault code P0509 in an automobile, start by checking the possible causes such as a dirty throttle body, misadjusted or damaged electric throttle control actuator, faulty electric throttle control actuator, intake air leak, or poor electrical connection to the Intake Air Control (IAC) valve.

2017年7月7日 · P0509故障码，适用于所有汽车制造商，意思是怠速空气控制系统电路高(Idle Air Control System Circuit High)。 提示：快速查找故障码，可以关注“ 车主指南 ”公众号，回复故障代码，如：“ P0509 ”，即可获得对应故障码解释和解决方案。

2020年6月14日 · Code P0509 Description. The Engine Control Module (ECM) controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is varied to allow for optimum control of the engine idling speed.

2023年11月21日 · p0509故障码怎么解决？ 故障码P0509涉及到怠速空气控制系统电路高的问题。 在处理此故障时，首先需要观察怠速马达在故障发生时的停留角度。

故障码p0509详细介绍如下 ： 故障所属系统范围：车速及怠速控制. 适用车型：所有汽车制造商. 中文含义解释：怠速控制系统-电路电压高. 英文含义：暂无. p0509故障码相关知识： 1.怠速空气控制iac系统的作用： 作用是控制发动机怠速空气量，稳定怠速。

How to diagnose, repair, and info on causes of a P0509 engine code which pertains to a high reading in the idle air control circuit. Also includes links to relevant forum topics on the code. Symptoms of P0509 OBD II Trouble Code