OBD2 Diagnostic Code
P0507
Idle Control System RPM Higher Than Expected — Why It Revs & How to Bring It Down
Your engine is sitting at a stop revving like it wants to go somewhere — and your car's computer noticed. Before anyone talks you into a new throttle body or idle air control valve, read this. In most cases the fix is a can of cleaner and 20 minutes of your time.
Severity
6 / 10
Moderate. Driveable short-term, but a sustained high idle causes real wear and should not be ignored.
Safe to Drive?
Conditionally
Short trips only. High idle strains the transmission and brakes. Avoid extended highway driving until fixed.
Typical DIY Fix Cost
Very Low – Low
Most cases resolved with throttle body cleaning or a vacuum hose — both very inexpensive repairs.
🔍 What This Code Means
Your engine has a target idle speed — typically between 600 and 800 RPM when fully warmed up. The ECM (engine control module) constantly monitors actual RPM against that target and makes small adjustments to keep idle smooth and steady.
P0507 fires when the ECM sees the actual idle RPM running significantly above its target — most commonly more than 200 RPM over the set point, often pushing past 1,200 RPM on a warm engine at a full stop. The computer tried to correct it, couldn't bring it down, and logged the fault.
💡 The opposite of P0507 is P0506 (idle RPM lower than expected). If you have both codes at once, the idle control system itself — not just a dirty throttle body — is likely the problem.
The good news is that a stuck-open throttle plate or a gummy idle air passage causes the overwhelming majority of P0507 cases. That is a cleaning job, not a parts replacement.
⚡ Common Symptoms
The high idle is usually obvious — but it does not always feel the same way in every car. Here is what to watch for.
RPM sits noticeably high at idle
Engine holds 1,200–2,000 RPM or higher when fully warmed up and sitting at a stop with no load.
Harsh or lurching gear engagement
Automatic transmissions slam harder into Drive or Reverse when engine RPM is elevated. You may feel a distinct thud.
Car creeps forward at stops
Higher idle means more torque at rest. The brake pedal needs more pressure than usual to hold the vehicle still.
Reduced fuel economy
The engine burns more fuel sitting at a high idle than it should. MPG drops noticeably on mixed-use driving.
RPM drops slowly after release
After letting off the gas, RPM hangs high for several seconds before gradually settling — or never fully settles.
Check engine light only
Some vehicles — especially newer ones with drive-by-wire throttle — show no obvious drivability issue beyond the warning light.
🎯 Most Likely Causes
Listed from most common to least common. Start at #1 every time. The majority of P0507 cases are solved before you reach cause #4.
1
Dirty throttle body — carbon buildup on the throttle plate
Over time, oil vapors from the PCV system coat the inside of the throttle body with sticky carbon deposits. This physically props the throttle plate slightly open, letting more air in than commanded. The ECM cannot compensate fully, so idle RPM climbs. This is the cause in roughly 4 out of 10 P0507 cases, and cleaning costs very little.
~ 40% of cases
2
Vacuum leak — unmetered air bypassing the throttle entirely
A cracked intake hose, loose PCV connection, or split vacuum line lets extra air enter the engine after the throttle plate. The ECM sees more air than it commanded — idle climbs. Leaks are often worse when cold and may improve as the engine warms and rubber expands slightly.
~ 28% of cases
3
Failed or stuck idle air control (IAC) valve
Older vehicles (pre-2005 roughly) use a dedicated IAC valve to regulate idle airflow separately from the throttle plate. If this valve sticks open, it passes excess air and raises idle. On drive-by-wire (electronic throttle) vehicles this component does not exist — on those, go straight to throttle body cleaning.
~ 15% of cases
4
Faulty coolant temperature sensor (ECT)
The ECM commands a higher idle when it thinks the engine is cold — this is normal warm-up behavior. If the coolant temp sensor sends a permanently cold signal, the ECM never reduces the fast idle. A sensor reading colder than ambient air temperature on a warm engine is a clear sign of failure. Sensor voltage at operating temp should read approximately 0.3–0.5V.
~ 9% of cases
5
Throttle position sensor (TPS) out of calibration
A TPS that reports a slightly open throttle when the pedal is fully released causes the ECM to see a commanded higher idle — and match it. Idle relearn procedures after battery disconnects sometimes expose this. Some vehicles require a throttle relearn via scan tool after throttle body cleaning.
~ 5% of cases
6
EVAP purge valve stuck open
The EVAP system purge valve is supposed to open only at cruise speed to route fuel vapors into the intake. If it sticks open at idle, it introduces an uncontrolled flow of fuel vapor — effectively adding unmetered air — and can raise idle RPM unpredictably. More likely if P0507 appears alongside EVAP-related codes such as P0441 or P0455.
~ 3% of cases
🔧 What to Check First
Three checks before spending anything. They take about 25 minutes, need no special tools, and catch the cause in the large majority of P0507 cases.
1
Clean the throttle body
With the engine cold, disconnect the air intake hose from the throttle body. You will see a round plate (the throttle blade) inside. Spray dedicated throttle body cleaner only onto a clean rag — never directly into a running engine — and wipe the plate and bore until no black carbon remains. Reconnect, clear the code, and let the engine idle for 10 minutes before evaluating. Many P0507 faults disappear with this step alone. Note: on some vehicles a throttle relearn is required after cleaning — check your owner's manual.
2
Inspect all vacuum hoses and PCV connections
With the engine off, trace every rubber hose connected to the intake manifold, throttle body, and valve cover. Squeeze each hose firmly at the bends — healthy rubber is supple. Cracked or brittle rubber crumbles under light pressure. Pay close attention to the large corrugated hose between the air filter box and throttle body, and the smaller PCV hose from the valve cover. A hissing sound from a loose fitting is a dead giveaway.
3
Check live coolant temperature on a scan tool
Plug in any OBD2 scanner and navigate to live data. Start the engine cold and watch the coolant temperature reading climb as the engine warms up. A healthy sensor reaches 190–210°F within 5–8 minutes of startup. If it never moves off a cold reading, or reads below 160°F on a fully warm engine, the coolant temp sensor is lying to the ECM — and commanding a permanently elevated idle as a result.
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⚠️ Common Misdiagnosis
These are the three repairs most commonly pushed for P0507 that turn out to be unnecessary. Knowing them before you authorize anything can protect your wallet significantly.
⚠ Misdiagnosis #1 — Throttle body replacement instead of cleaning
A throttle body clogged with carbon buildup behaves identically to a failing one on a scan tool. The correct first step is always to clean it thoroughly and retest over a full drive cycle. If a shop quotes a new throttle body without attempting a cleaning service first, ask them to document why cleaning was skipped. The price difference between cleaning and replacement is very significant.
Potential savings: Substantial — cleaning vs. full throttle body replacement
⚠ Misdiagnosis #2 — IAC valve replaced before vacuum leak check
On vehicles equipped with an IAC valve, shops sometimes replace it immediately when P0507 appears. But a vacuum leak produces a near-identical high-idle symptom. Checking every vacuum hose and connection costs nothing and takes 10 minutes. Replacing the IAC valve on a car that actually has a cracked PCV hose solves nothing and wastes money. Always rule out vacuum leaks first.
Potential savings: Significant — valve replacement vs. a cheap hose
⚠ Misdiagnosis #3 — Throttle position sensor replaced without calibration attempt
When a TPS appears out of range on a scan tool, replacement is not always necessary. Many vehicles allow the ECM to relearn the throttle position through a simple key-cycle or scan tool procedure. On drive-by-wire vehicles especially, a throttle relearn after battery disconnect or throttle body cleaning will often resolve a false TPS reading without touching the sensor itself.
Potential savings: Moderate — relearn procedure vs. sensor replacement
💰 Estimated Repair Cost
DIY cost = parts and supplies only. Shop cost = parts plus labor. Ranges vary by vehicle, region, and shop rate. Use these as a planning reference, not a fixed quote.
Throttle body cleaning
DIYMinimal
ShopLow
LevelVery Easy
Vacuum hose replacement
DIYVery Low
ShopLow–Moderate
LevelEasy
PCV valve replacement
DIYVery Low
ShopLow
LevelVery Easy
IAC valve replacement
DIYLow
ShopModerate
LevelEasy–Moderate
Coolant temperature sensor replacement
DIYLow
ShopModerate
LevelModerate
Throttle position sensor replacement
DIYLow–Moderate
ShopModerate
LevelModerate
Throttle body replacement (assembly)
DIYModerate–High
ShopHigh
LevelAdvanced
✅ In the majority of confirmed P0507 cases, the total repair cost is minimal when you start with cleaning and vacuum inspection before considering any parts replacement.
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🚗 Most Reported On
P0507 can appear on any gasoline-powered vehicle. These models report it most frequently based on owner data and verified repair records.
Honda Civic (2006–2015, 1.8L / 2.0L)
Honda CR-V (2007–2016, 2.4L)
Toyota Camry (2007–2014, 2.4L / 2.5L)
Toyota Corolla (2009–2018, 1.8L)
Nissan Altima (2007–2015, 2.5L)
Nissan Sentra (2013–2019, 1.8L)
Chevrolet Cruze (2011–2016, 1.4L Turbo)
Ford Focus (2012–2018, 2.0L)
Hyundai Elantra (2011–2016, 1.8L / 2.0L)
❓ Frequently Asked Questions
Can I drive with P0507 active?
Generally yes, for short trips — the car will run, but a high idle puts extra load on the transmission and brakes, and fuel economy suffers. If the RPM climbs dangerously high (above 2,000 at a full stop), drive as little as possible until the problem is fixed.
Why does P0507 come back after I clear it?
Clearing the code only removes the warning light. The underlying condition — most often a dirty throttle body or a vacuum leak — is still present. The ECM will re-detect the high idle within a drive cycle or two and set P0507 again. Fix the root cause first, then clear the code and test over a full drive cycle.
What is a normal idle RPM?
For most passenger cars and light trucks, a healthy warm idle sits between 600 and 800 RPM. Some performance engines idle slightly higher. P0507 is triggered when the ECM sees the actual RPM running roughly 200 RPM or more above its target, typically crossing the 1,200 RPM threshold on a fully warm engine.
Can a bad coolant temperature sensor cause P0507?
Yes. If the ECM thinks the engine is still cold when it is actually warm, it will continue commanding a high fast idle. A coolant temperature sensor reporting an incorrect signal is a legitimate cause of P0507, though less common than throttle body or vacuum issues. Testing the sensor with a scan tool's live data is the fastest way to confirm — watch the temperature reading climb as the engine warms up from a cold start. A stuck or very slow reading is a red flag.
Does P0507 affect the transmission?
It can. When idle RPM is significantly elevated, automatic transmissions experience harder engagement when shifting into Drive or Reverse — you may feel a noticeable thud or lurch. Over time, repeated high-RPM gear engagement increases wear on transmission bands and clutch packs. Resolving P0507 promptly protects both the engine and the transmission.
🔗 Related Codes
These codes share similar root causes or commonly appear alongside P0507.
This guide is for informational purposes only. Always consult a qualified mechanic before performing any vehicle repair. OBDPlatform is not responsible for actions taken based on this content.