Idle Air Control System
Table of contents
P0505 TOYOTA Possible 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)
How do I fix code P0505 TOYOTA?
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’s pins.
Tech Notes
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Cost of diagnosing the P0505 TOYOTA code
The cost of diagnosing the P0505 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine hard to start
- Rough or erratic idle speed
P0505 TOYOTA Description
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.