Is it safe to drive with a P0505 code?

Severity is medium. Address P0505 sooner rather than later — driving with an active check engine light can worsen the problem or void emissions warranties.

How much does it cost to fix P0505?

Repair costs for P0505 typically range from $15 to $250 in the US, depending on the underlying cause. The most common fix is: Carbon buildup in the IAC valve (cleaning often fixes it).

What are the symptoms of P0505?

Check engine light. High or low idle. Stalling at stops. Surging at idle.

Check Engine Code

P0505

Idle Air Control System Malfunction

Severity: medium DIY difficulty: 2/5 Typical cost: $15–$250

Last updated April 30, 2026

What P0505 means

Older (non-drive-by-wire) cars use an idle air control (IAC) valve to let a metered amount of air bypass the throttle plate at idle. P0505 means the ECM and the IAC aren't agreeing.

Symptoms

Check engine light
High or low idle
Stalling at stops
Surging at idle

Likely causes (most common first)

Carbon buildup in the IAC valve (cleaning often fixes it)
Failed IAC motor
Vacuum leak masking as an IAC problem
Dirty throttle body
Wiring fault

Can I keep driving?

Medium — drivable but fix soon

Typical repair cost

DIY fixes can start near $15 (parts only). Shop repairs for P0505 typically run up to $250 depending on the underlying cause and vehicle. Start with the most common cause — Carbon buildup in the IAC valve (cleaning often fixes it) — before throwing parts at it.

Recommended parts & tools for P0505

Most common fix for P0505:

Throttle body cleaner

Our buyer’s guides cover the tools and parts that pair with AXLY:

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Related codes

P0506 P0507

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