P0505
Medium SeverityIdle Air Control System
Engine System
What Does P0505 Mean?
The idle air control (IAC) valve is not maintaining proper idle speed.
Common Fix
Clean or replace IAC valve
Estimated Cost (DIY)
$10 - $80
Symptoms
- ⚠️Erratic idle speed
- ⚠️Stalling when coming to a stop
- ⚠️High idle
- ⚠️Hunting idle
Common Causes
How to Diagnose P0505
- 1Clean IAC valve and port
- 2Clean throttle body
- 3Check for vacuum leaks
- 4Replace IAC if cleaning does not help
OEM Diagnostic Flowchart
Scroll to load technician if/then branches.
Read live data and freeze frame for P0505 to pinpoint the cause before buying parts.
Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0505.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 Toyota Corolla L4-1.8L (2ZR-FE) Service Manual | Operation CHARM Operation CHARM : Car repair...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 Toyota Corolla L4-2.4L (2AZ-FE) Service Manual | Operation CHARM Operation CHARM : Car repair...
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A L L Diagnostic Trouble Codes ( DTC ) — 2012 Ford Truck Flex AWD V6-3.5L Turbo Service Manual | Operation CHARM Operation CHARM : Car repa...
Exact Vehicle Hubs
Browse →Open the exact vehicle hub grounded by OEM manual evidence related to P0505.
Open the exact vehicle hub grounded by OEM manual evidence related to P0505.
Open the exact vehicle hub grounded by OEM manual evidence related to P0505.
Open the exact vehicle hub grounded by OEM manual evidence related to P0505.
Related Codes
Frequently Asked Questions
- Can I clean the IAC valve?
- Yes — remove it and spray the pintle and port with throttle body cleaner. This fixes P0505 about 60% of the time.
- What is normal idle speed?
- Most engines idle at 600-800 RPM when warm. Higher or lower than this range indicates an idle control problem.