OBD2 fault code
HighP0505
Idle Control System Malfunction
The code identifies an implausible condition in the monitored system. The component named in the code is not automatically the defective part.
What does P0505 mean?
Idle Control System Malfunction. The engine or vehicle control system detected that a measured value, control response, or communication signal was outside the expected range.
Common symptoms
- idle too high, low, or unstable
- engine stalls when coasting
- poor throttle response
Likely causes
- dirty throttle body or incorrect adaptation
- vacuum leak or faulty idle control valve
- mixture, sensor, or ignition issue
Sensible diagnostic order
- inspect throttle body and intake
- compare idle target/actual values and fuel trims
- perform adaptation only according to manufacturer procedure
Can I continue driving?
Only if the vehicle runs normally; avoid heavy load. If the check-engine light flashes, the engine shakes strongly, warning messages increase, or power drops significantly, stop and arrange professional assistance.
This information is a diagnostic aid and does not replace inspection by a qualified workshop. Manufacturer-specific definitions may differ.
FAQ
Can I continue driving with P0505?
Only if the vehicle runs normally; avoid heavy load.
Does P0505 always identify a defective part?
No. A fault code identifies a monitored system or implausible condition. Wiring, voltage, leaks, and related components must also be checked.
How can DiagnostiX help with P0505?
DiagnostiX reads the code from the vehicle, assigns it to the vehicle profile, and displays relevant live values and a structured explanation.