Owner decision guide
P0507 idle speed higher than expected
P0507 means actual idle stayed above the commanded range. Unmetered air, a sticking throttle, incorrect relearn, purge flow, PCV faults and cable interference are more useful starting points than an idle-speed screw. Before acting, check Idle speed cold and fully warm, Throttle angle, fuel trims and purge command, Intake leaks and recent battery or throttle work. Record the exact condition, since temperature, speed, load and warning status all change the diagnosis. The sections below break this down further: why idle rises, the relearn step people skip, safety considerations, finding a vacuum leak. This is rated soon risk: Stop if engine speed surges uncontrollably, braking cannot hold the vehicle, or the throttle does not return normally. 4 related questions are answered separately below. Reviewed under this site's evidence-first standard, sourced to EPA OBD and emissions guidance, with related obd codes and emissions guides linked at the end.
Evidence first
P0507 means idle speed was higher than the module's target by more than the allowed margin. On drive-by-wire engines the module controls idle through the electronic throttle, so an idle it cannot pull down usually means air is entering somewhere it is not being measured or the throttle is not closing as commanded.
Vacuum leaks and a dirty throttle body account for most cases.
Why idle rises
Anything admitting extra air, or preventing the throttle plate from reaching its commanded position.
- Vacuum leaks at intake hoses, gaskets or the brake booster
- Carbon buildup on the throttle body preventing full closure
- A stuck or leaking PCV valve
- A throttle body needing its idle relearn procedure after cleaning
- A binding throttle cable on older mechanical systems
- A failing idle air control valve on engines that still use one
The relearn step people skip
On many vehicles, cleaning the throttle body without performing the idle relearn procedure leaves the module using stored values that no longer match the cleaned throttle, and idle stays wrong.
The procedure varies by manufacturer: some require a scan tool, others a specific key-on sequence. Skipping it is a common reason a repair appears not to work.
Safety considerations
A high idle increases creep in gear and lengthens stopping distance in slow manoeuvring, particularly when parking.
If the idle is high enough that the vehicle creeps forcefully against the brakes, treat it as urgent instead of cosmetic.
Finding a vacuum leak
A smoke test is the reliable method: low-pressure inert smoke is introduced into the intake with the engine off, and it escapes wherever the seal has failed. Leaks too small to hear are visible immediately.
Listening with a length of hose, or spraying a small amount of carburettor cleaner near suspect joints and watching for an idle change, are field techniques that find larger leaks. Both are less reliable than a smoke test and the spray method carries a fire risk near hot components.
- Smoke testing finds leaks too small to hear
- Check the intake boot, PCV hoses and brake booster line
- Intake manifold gaskets fail with age and heat cycling
- Spray testing near hot components carries a fire risk
What to check before acting
| # | Check | Why it matters |
|---|---|---|
| 01 | Idle speed cold and fully warm | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
| 02 | Throttle angle, fuel trims and purge command | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
| 03 | Intake leaks and recent battery or throttle work | Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis. |
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Record the exact condition; differences in temperature, speed, load and warning status change the diagnosis.
Safe sequence
What to do next
| Step | Action |
|---|---|
| 1 | Check floor mats and throttle movement with the engine off |
| 2 | Inspect and smoke-test the intake |
| 3 | Perform the specified throttle cleaning or relearn only when indicated |
- 1
Check floor mats and throttle movement with the engine off
- 2
Inspect and smoke-test the intake
- 3
Perform the specified throttle cleaning or relearn only when indicated
Avoid making it worse
What not to do
- Do not adjust sealed throttle stops
- Do not spray cleaner into an electronic throttle while powered
Stop if engine speed surges uncontrollably, braking cannot hold the vehicle, or the throttle does not return normally.
Source and scope
Common questions
Is a high idle dangerous?
It can be. Increased creep in gear makes slow manoeuvring and parking harder, and a strongly elevated idle should be corrected promptly.
Can cleaning the throttle body cause this code?
Yes, if the idle relearn procedure is not performed afterward. The module keeps stored values that no longer match the cleaned throttle.
How do I find a vacuum leak?
A smoke test is the reliable method. Visual inspection of hoses and the intake boot finds the larger ones.
Will the idle come down on its own?
Only if the cause was a temporary adaptation. A genuine leak or throttle fault will not resolve itself.