OBD · Air intake and boost
P0505 Idle air control system
What this code means
P0505 is a generic OBD code shared by all manufacturers since 2001 for petrol and 2004 for diesel. It relates to: air intake and boost. The code tells you what the ECU measured as abnormal, not necessarily which part to replace.
Most common causes
- Intake air leak#1
A hiss at idle with an unstable idle often means a split hose or intake gasket.
How to read this code
An OBD scanner plugged into the 16-pin socket under the steering wheel reads and clears codes. Bluetooth models cost £20 to £40. Clearing a code without fixing the fault is pointless: it comes back.
Related problems
Frequently asked questions
What does code P0505 mean?
P0505: Idle air control system. P0505 is a generic OBD code shared by all manufacturers since 2001 for petrol and 2004 for diesel. It relates to: air intake and boost. The code tells you what the ECU measured as abnormal, not necessarily which part to replace.
Can I drive with code P0505?
Monitor. You can drive normally but get it checked in the coming weeks. It may fail an MOT or roadworthiness test.
How to read this code
An OBD scanner plugged into the 16-pin socket under the steering wheel reads and clears codes. Bluetooth models cost £20 to £40. Clearing a code without fixing the fault is pointless: it comes back.