Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Idle speed is controlled by Electronic Throttle Control System (ETCS). ETCS is composed of throttle motor, magnetic clutch, TP sensor, accelerator pedal position sensor, ECM and throttle body. ECM controls throttle motor to adjust throttle valve opening angle. DTC P0505 is set if idle speed continues to vary greatly from target speed. Possible causes are:
- Faulty ETCS.
- Leaking air intake system.
- Faulty PCV hose connection.
- Faulty ECM.
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.