P0505 Error Code
📋 What Does P0505 Mean?
Idle Control System Malfunction — idle speed is erratic or not controlled correctly.
🔍 Common Causes
- 1Dirty throttle body (common after 60,000+ miles)
- 2Faulty idle air control valve
- 3Vacuum leak
- 4Dirty MAF sensor
- 5Throttle position sensor fault
📞 When to Call a Pro
If idle is still erratic after cleaning, throttle body or sensor replacement needed.
🔧 DIY Fix Steps
- 1Clean the throttle body with throttle body cleaner — this is one of the most effective DIY fixes
- 2Clean MAF sensor
- 3Check vacuum hoses for cracks or disconnections
- 4Perform idle relearn procedure after throttle body cleaning: key off, wait 10 seconds, start engine, allow to idle 10 minutes without touching accelerator
Frequently Asked Questions
What does P0505 mean on a Toyota vehicle?
Idle Control System Malfunction — idle speed is erratic or not controlled correctly.
Can I fix P0505 myself?
Yes, in many cases. Start with: clean the throttle body with throttle body cleaner — this is one of the most effective diy fixes If that does not resolve it, if idle is still erratic after cleaning, throttle body or sensor replacement needed.
How much does it cost to repair error P0505?
Estimated repair cost: $80–$350. This varies by region and technician.
Tools That Help With This Diagnosis
Basic troubleshooting tools grouped separately from the actual error-code explanation.
Multimeters
Useful for basic electrical checks when the repair path calls for it and the unit is safely isolated.
Driver sets
Useful when the first obstacle is simply reaching the part or hose involved.
Cleanup tools
Useful for drain and leak faults where standing water hides the problem.
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