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.
DTC P0505 Idle Control System Malfunction: Description
The idle speed is controlled by the ETCS (Electronic Throttle Control System). The ETCS is comprised of: 1) a one valve type throttle body; 2) a throttle actuator, which operates the throttle valve; 3) a Throttle Position (TP) sensor, which detects the opening angle of the throttle valve; 4) an Accelerator Pedal Position (APP) sensor, which detects the accelerator pedal position; and 5) the ECM (included in hybrid vehicle control ECU), which controls the ETCS. Based on the target idle speed, the ECM controls the throttle actuator to provide the proper throttle valve opening angle.
| DTC No. | DTC Detection Conditions | Trouble Areas |
|---|---|---|
| P0505 | Idling speed continues to vary greatly from target idling speed (2-trip detection logic) |
|
NO RELATED
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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.