P0505 on Volvo
Idle Air Control System Malfunction
P0505 on Volvo vehicles indicates idle air control system malfunction. Au7o has documented this code across 2 Volvo models — most commonly on S70, XC60. P0505 indicates a malfunction in the idle air control (IAC) system, which manages how much air bypasses the throttle plate to keep the engine idling smoothly at the correct RPM. On older systems this is a dedicated IAC valve/motor; the computer uses it to raise idle for cold starts, A/C load, or accessory load. When the system can't maintain the target idle, you may get a high or low idle, surging, rough idle, or stalling — especially at stops or when cold. The cause is usually a dirty or failed IAC valve, but vacuum leaks and electrical faults are common too. Typical repair costs on Volvo range from $100 to $600, depending on the specific model and root cause.
Common Causes of P0505
- •Dirty or carbon-clogged idle air control valve
- •Failed IAC valve motor or stuck pintle
- •Vacuum leak in the intake system
- •Dirty throttle body or sticking throttle plate
- •Wiring or connector fault in the IAC circuit
- •Faulty PCV system causing unmetered air
- •PCM/ECM control fault
P0505 on Volvo by Model
Volvo S70(1 issue)
- PCV System Clogging and Oil Leaks1998-2000
The Volvo S70 turbo and non-turbo 5-cylinder engines develop PCV (Positive Crankcase Ventilation) system blockage. The breather box/flame trap clogs, causing excessive crankcase pressure that pushes oil past gaskets and seals.
Volvo XC60(1 issue)
- PCV Oil Trap/Separator Failure2010-2015
The Volvo XC60 with the 3.0L and 3.2L inline-6 engines develops oil trap (PCV separator) failures. The oil trap membrane degrades, causing excessive oil consumption, rough idle, and oil leaks from pressurized seals.
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View P0505 across all makes →Frequently Asked Questions
What does P0505 mean on Volvo?▼
P0505 stands for "Idle Air Control System Malfunction." P0505 indicates a malfunction in the idle air control (IAC) system, which manages how much air bypasses the throttle plate to keep the engine idling smoothly at the correct RPM. On older systems this is a dedicated IAC valve/motor; the computer uses it to raise idle for cold starts, A/C load, or accessory load. When the system can't maintain the target idle, you may get a high or low idle, surging, rough idle, or stalling — especially at stops or when cold. The cause is usually a dirty or failed IAC valve, but vacuum leaks and electrical faults are common too. On Volvo specifically, this code is documented across 2 models.
What causes P0505 on Volvo vehicles?▼
Common causes on Volvo: Dirty or carbon-clogged idle air control valve, Failed IAC valve motor or stuck pintle, Vacuum leak in the intake system, Dirty throttle body or sticking throttle plate, Wiring or connector fault in the IAC circuit. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0505 on a Volvo?▼
Repair costs on Volvo range from $100 to $600, depending on the specific model and root cause.
Which Volvo models have P0505 documented?▼
Au7o has documented P0505 on 2 Volvo models: S70, XC60.