P0505 2004 Toyota Highlander Code - Idle Air Control System
Quick Answer
The idle speed is controlled by the Electronic Throttle Control System (ETCS). Common causes include Dirty Throttle Body, Faulty Electronic Throttle Control System (ETCS) (Throttle body), Electronic Throttle Control System harness is open or shorted. 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 2004 Toyota Highlander indicates Idle Air Control System.
- Common causes
- Common causes include Dirty Throttle Body, Faulty Electronic Throttle Control System (ETCS) (Throttle body), Electronic Throttle Control System harness is open or shorted.
- 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.
Code P0505 2004 Toyota Highlander Description
The ECM regulates the idle speed by opening and closing the throttle valve using the ETCS. The ECM concludes that the idle speed control ECM function is malfunctioning and set the Diagnostic Trouble Code (DTC) if:
1. The actual idle RPM varies more than the specified amount five times or more during a drive cycle
2. The learning value of the idle speed control remains at the maximum or minimum five times or more during a drive cycle.
Example: If the actual idle RPM varies from the target idle RPM by more than 200* rpm five times during a drive cycle, the ECM will turn on the MIL and will set a DTC.
What are the Possible Causes of the DTC P0505 2004 Toyota Highlander?
- Dirty Throttle Body
- Faulty Electronic Throttle Control System (ETCS) (Throttle body)
- Electronic Throttle Control System harness is open or shorted
- Electronic Throttle Control System circuit poor electrical connection
- Air Induction System (Intake leak)
- PCV hose connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0505 2004 Toyota Highlander?
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 is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0505 2004 Toyota Highlander 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.
Need more information about the P0505 2004 Toyota Highlander code?
Need more information on how to fix the P0505 2004 Toyota Highlander code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0505 2004 Toyota Highlander code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0505 2004 Toyota Highlander Code
1. What does OBDII code P0505 mean on a 2004 Toyota Highlander?
P0505 indicates a problem with the Idle Air Control (IAC) system, which regulates the engine's idle speed.
2. What are common symptoms of code P0505 on a 2004 Toyota Highlander?
Symptoms include rough idle, stalling, fluctuating idle speed, and possibly an illuminated Check Engine Light.
3. What causes the P0505 code on a Toyota Highlander?
Common causes include a faulty IAC valve, carbon buildup in the throttle body or IAC valve, wiring issues, or a vacuum leak.
4. Can I drive my 2004 Toyota Highlander with a P0505 code?
It’s possible to drive short distances, but you may experience stalling or poor engine performance, which could create unsafe driving conditions.
5. How do I diagnose the P0505 code on a Toyota Highlander?
Check for vacuum leaks, inspect the IAC valve for damage or clogging, test the IAC valve's electrical connections, and clean the throttle body.
6. Can a dirty throttle body cause the P0505 code?
Yes, carbon buildup in the throttle body can restrict airflow and trigger the P0505 code.
7. How do I fix a P0505 code on my 2004 Toyota Highlander?
Clean the throttle body and IAC valve, check for and repair vacuum leaks, and replace the IAC valve if it’s faulty.
8. What tools are needed to fix the P0505 code?
You’ll typically need a multimeter, a socket set, throttle body cleaner, and possibly a replacement IAC valve.
9. How much does it cost to repair the P0505 code on a Toyota Highlander?
The cost varies but cleaning the throttle body is inexpensive, while replacing the IAC valve could cost $150–$300, including parts and labor.
10. Can a vacuum leak cause the P0505 code?
Yes, a vacuum leak can disrupt the idle air control system and cause the P0505 code to appear.
Discuss the causes and fixes for P0505 2004 Toyota Highlander OBDII Code
Code P0505 2004 Toyota Highlander comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
