Engine-Codes - Toyota - P0505 2003 Toyota Highlander

P0505 2003 Toyota Highlander Code - Idle Air Control System

- Code Popularity: 5,521 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0505 2003 Toyota Highlander?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • 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)
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How to Fix the DTC P0505 2003 Toyota Highlander?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0505 2003 Toyota Highlander code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Engine hard to start
  • Rough or erratic idle speed

What Does the P0505 2003 Toyota Highlander Code Mean?

The idle speed is controlled by the Electronic Throttle Control System (ETCS). The ETCS is composed of the throttle motor, which operates the throttle valve, and the throttle position sensor, which detects the opening angle of the throttle valve. The Engine Control Module (ECM) controls the throttle motor to provide the proper throttle valve opening angle to obtain the target idle speed.
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.

P0505 2003 Toyota Highlander Code - Idle Air Control System

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