P0507: Idle Control System RPM Higher Than Expected
P0507 means the engine idles faster than the computer's target even though the idle control is already at its minimum. It is usually not an emergency, but it should be fixed because it turns on the check engine light and can make the car creep at stops.
You can drive, but get it checked soon
The car normally keeps running and limp mode is not expected, but a high idle can make an automatic creep forward at a standstill and makes braking at stops less comfortable. Have it checked soon, and keep your foot firmly on the brake when stopped.
What it means
The engine computer monitors idle speed and compares it with a target. For gasoline engines, the code is set when idle stays too high (the data names a margin of +200 rpm as the monitoring limit, and individual manufacturers use their own thresholds). Older engines have a separate idle air control valve that lets air bypass the closed throttle. On cars with an electronic throttle, the throttle itself controls idle and no separate valve exists. With P0507, the computer has already reduced the air as far as it can, yet the engine still runs too fast. That points to extra air getting in somewhere it should not (called false air or a vacuum leak), or to a throttle that does not close fully. The code is emissions relevant, so the check engine light comes on, and the car may need a drive cycle (a set pattern of driving) before the monitor confirms the repair.
Likely causes
- False air (vacuum hose, intake gasket, brake booster)Very likely
Air that enters the engine past the throttle is not accounted for, so the engine speeds up and the computer cannot bring it down; this is the classic cause.
- Crankcase ventilation leaking or wrongly routedPossible
A leaking or misrouted crankcase ventilation hose lets in extra air in the same way as a vacuum leak.
- Throttle not closing fully (deposits, ice, stop misadjusted)Possible
If the throttle stays slightly open, more air gets through than the computer intends.
- Idle valve stuck openPossible
On engines with a separate idle valve, one stuck open keeps letting air bypass the throttle.
- Wrong throttle learned value after cleaning or replacementLess likely
After the throttle is cleaned or replaced, the computer may hold an old closed-position value that no longer fits, so idle air is set too high.
What you may notice
- Idle speed too high
- Automatic car creeps at standstill
- Hissing sound from a vacuum leak
- Check engine light on
What to check, cheapest first
- 1Listen with the engine idling for hissing near the intake and the hoses, and look for cracked, loose or disconnected vacuum hoses. · you can do it
- 2Check the crankcase ventilation hoses and connections for cracks, leaks or incorrect routing, and the dipstick and oil cap for proper seating. · you can do it
- 3Inspect the throttle body for deposits or a sticking throttle plate, and in cold weather consider whether ice could be holding it open. · you can do it
- 4If the throttle was recently cleaned or replaced, have the throttle relearn (idle adaptation) procedure performed. · mechanic
- 5Smoke-test the intake to find false air at the intake gasket, brake booster or its hose. · mechanic
- 6Check the idle valve (if the car has one) and the throttle's stop adjustment, and review live data to see idle speed against target. · mechanic
Related codes
Frequently asked questions
Can I drive with P0507?+
Usually yes for a short time, since limp mode is not expected. The high idle can make an automatic creep at stops, so get it checked soon.
Can a gas cap cause P0507?+
The reference data does not list the gas cap as a cause. Look first for vacuum leaks, crankcase ventilation problems and a throttle that does not close.
Will P0507 pass an emissions test?+
Probably not while the check engine light is on, because the code is emissions relevant. After the repair, a drive cycle may be needed before the system is ready for testing.
Can I fix it myself?+
Often yes. The repair is rated medium difficulty and takes roughly 0.5 to 2 hours, for example replacing a hose or cleaning the throttle.
Written with the help of AI from the public OBDex definition (CC0). Each make may use the code differently. Updated: 2026-11-10