P0507 — Idle Control System RPM - Higher Than Expected
P0507 means the idle speed is higher than the computer expects and cannot be pulled down — usually a vacuum leak, a dirty throttle body, or a sticking idle control component feeding the engine extra air.
Severity: Low · Can you keep driving? Yes, with awareness: a high idle makes the car creep harder against the brakes and can surge, so leave extra room until it is fixed.
What the P0507 code means
Idle speed is a controlled balance: the computer meters exactly enough air past the throttle (or through an idle air control valve on older designs) to hold its target rpm against the engine's loads. P0507 sets when actual idle sits persistently above that target — often 100–200 rpm or more — despite the computer closing the air path as far as it can.
Extra air is almost always the story. Air that bypasses the throttle's control — through a split PCV hose, a leaking intake gasket, a brake booster hose — raises idle exactly like opening the throttle slightly. So does a throttle plate that cannot close fully because its bore is ringed with carbon, and so does a purge valve stuck open, sipping vapor and air from the tank.
One modern cause surprises people: after a battery disconnect or throttle cleaning, some engines must relearn their idle strategy. Until the relearn completes, idle can sit high or hunt. That is a procedure problem, not a parts problem, and it is why the history of recent work matters in diagnosis.
Symptoms of P0507
- Idle speed noticeably high — for example 900–1,200 rpm in gear instead of the usual 600–750
- The car creeps forward more eagerly and needs firmer brake pressure at stops
- Surging or hunting idle in some cases
- Harder, clunkier engagement when shifting from park into drive or reverse
- Check engine light; fuel economy slightly worse
What causes P0507?
- Vacuum leak — split PCV hoses and valves, intake gaskets, and booster hoses admit air the throttle never authorized. The most common cause — the engine is idling on air the computer cannot close off.
- Carbon-fouled throttle body — deposits around the throttle plate stop it sealing at its learned closed position, so the effective opening stays too large. Cleaning plus an idle relearn is the standard cure.
- Faulty idle air control valve (older designs) — the motorized pintle that bypasses the throttle sticks open with carbon and age, or its motor fails in the open position.
- EVAP purge valve stuck open — a continuous draw of vapor from the tank adds fuel and air at idle, pushing speed up and often bringing EVAP or rich codes along.
- PCV valve stuck open — an open PCV path is a calibrated vacuum leak straight into the intake — cheap part, classic cause.
- Idle relearn not completed — after battery disconnection, throttle cleaning, or part replacement, some ECUs need a defined relearn drive cycle; until then the idle target strategy is wrong.
How serious is P0507?
Nothing here damages the engine, and the code is low severity in the mechanical sense. The driving consideration is real, though: a car idling several hundred rpm high pushes noticeably against its brakes, engages gears with a thump, and can surge unexpectedly in parking maneuvers. Treat it with a bit of respect in tight spaces.
It will fail an emissions inspection while stored, and its causes overlap with lean codes — a vacuum leak left alone tends to grow until P0171 joins it. Fix at normal priority.
How much does it cost to fix P0507?
This is a diagnosis-friendly code: most causes are external and inexpensive. Typical US costs, parts and labor:
| Repair | Typical US cost (parts & labor) |
|---|---|
| Throttle body cleaning and idle relearn | $100–$200 |
| PCV valve or vacuum hose replacement | $50–$250 |
| Idle air control valve replacement (where fitted) | $200–$450 |
| Electronic throttle body replacement | $400–$900 |
Prices are typical US ranges and vary by vehicle, location, and shop. Diagnosis usually costs $100–$150 and is often applied to the repair bill if you proceed at the same shop.
How P0507 is diagnosed and fixed
- Confirm the complaint in live data: read actual idle rpm against the computer's desired idle, warm, in park and in gear, with accessories on and off.
- Ask about recent work. A battery disconnect or throttle service immediately before the code suggests a relearn procedure before any parts.
- Inspect and smoke-test the intake path: PCV hoses and valve, intake gaskets, brake booster hose, and every vacuum line, listening for hissing at idle.
- Inspect the throttle bore and plate for carbon; clean with throttle-body cleaner (never scrape an electronic unit) and perform the manufacturer's idle relearn.
- Check the purge valve for vacuum pass-through at rest and the idle air control valve (if fitted) for sticking and correct commanded movement.
- Repair the cause, clear codes, complete the relearn drive cycle, and verify idle sits at target in all load states.
Frequently asked questions
What causes a P0507 code?
Air getting in that the computer cannot shut off: vacuum leaks lead, then a carbon-fouled throttle plate that cannot close, a sticking idle air control valve on older engines, a purge valve stuck open, or simply an idle relearn that was never completed after battery or throttle work.
How much does it cost to fix P0507?
Most fixes are at the cheap end: $50–$250 for PCV and vacuum parts, $100–$200 for a throttle cleaning and relearn. An idle air control valve runs $200–$450 and a full electronic throttle body $400–$900 if it truly has failed. Prices vary by vehicle, location, and shop.
Can I drive with P0507?
Yes. Just remember the car will creep harder at stops and may engage gears with a clunk — keep a firmer foot on the brake. The code harms nothing mechanically, but its causes (like vacuum leaks) tend to worsen, so fix it at normal priority.
Why is my idle high after a battery change?
Many engines keep their idle strategy in memory that is lost when power is disconnected. Until the relearn drive cycle completes — a defined pattern of idling and driving that varies by maker — idle can sit high or hunt. It is a procedure, not a failure, and P0507 is its calling card.
Can a dirty throttle body really raise idle?
Yes. Carbon builds a ridge where the plate seals. The computer's learned 'closed' position then leaves a crescent of open bore, admitting extra air on every start. A careful cleaning and an idle relearn usually restore the target speed exactly.
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