What does Error Code P0505 mean?
Moderate Issue
DTC Code P0505 indicates an Idle Control System Malfunction where the Idle Air Control Valve (IACV) and Auxiliary Air Control (AAC) Valve fail to properly adjust the air bypass passage, affecting engine idle speed. This malfunction is detected when the IACV-AAC valve does not operate as per the Engine Control Module (ECM) signals.
What are the symptoms of Error Code P0505?
- Engine Light ON: The check engine light or service engine soon warning light illuminates, indicating a potential issue with the idle control system.
- Engine Hard to Start: Difficulty in starting the engine, which may be linked to a malfunction in the idle control system affecting air intake regulation.
- Rough or Erratic Idle Speed: The engine may experience rough or fluctuating idle speeds, suggesting a problem with the idle air control valve or related components.
What causes Error Code P0505?
- The Idle Air Control Valve (IACV-AAC) may be malfunctioning, leading to improper regulation of engine idle speed.
- An open or shorted harness in the IACV-AAC valve can disrupt the electrical signals necessary for proper idle control.
- Poor electrical connections in the IACV-AAC valve circuit can cause intermittent or complete failure of the idle control system.
Find the Root Cause with AI
Analyze symptoms and error codes with artificial intelligence for a precise diagnosis
Fast Diagnosis in under 3 minutes
Precise AI-powered analysis
Free No hidden fees
Data-Driven Over 40,000 reference cases
How to fix Error Code P0505?
- Initial Inspection: Check for any vacuum leaks in the intake system, as these can affect idle control. Inspect hoses and connections for damage or disconnection.
- Throttle Body Inspection: Inspect the throttle body for carbon buildup or obstruction. Clean the throttle body if necessary to ensure proper airflow.
- Idle Air Control Valve (IACV) Check: Test the Idle Air Control Valve for proper operation. Ensure it is not stuck or malfunctioning, as this can cause idle issues.
- Electrical Connections: Inspect electrical connections to the IACV and throttle body. Ensure there are no loose or corroded connections that could affect performance.
- ECU and Sensor Check: Verify that the Engine Control Unit (ECU) is functioning correctly and that sensors related to idle control are providing accurate data.
- Related Codes Analysis: Review related codes P0506 and P0507 to determine if the idle RPM is consistently too high or too low, which can help pinpoint the issue.