P0507 Code: Idle Control System RPM Higher Than Expected

What the P0507 code means

The computer sets a target idle speed and holds it by metering the air that enters the engine. Depending on the system, it does that by moving the throttle plate slightly or through a dedicated idle air valve.

The P0507 code is stored when the actual idle speed rises above that target by more than the allowed tolerance, usually 200 to 300 rpm, and the system cannot bring it back down.

The diagnostic logic is simple once you understand the problem. If the engine is spinning faster than commanded, more air is getting in than the computer is metering. And that extra air has to come from somewhere.

The possible places are few. A vacuum leak in the hoses, the intake manifold gasket, the PCV valve or the brake booster. A throttle plate that does not close all the way because carbon holds it slightly open. A stuck idle valve. Or simply adaptations that were not reset after the throttle body was cleaned, which leaves the system working from the wrong reference.

It is worth knowing that this code confirms itself in an unusual way. The system does not only measure the speed. It also checks that its own corrections are failing to bring it down. If the computer has already closed its air metering all the way and the engine still spins high, the conclusion is unavoidable: air is entering through a path the system does not control. That logic is why a vacuum leak search is almost always the right road.

Check whether the high idle only shows up with an accessory running. The air conditioning, the power steering during a turn and the alternator under load all make the computer raise the idle on purpose to compensate, and that increase is normal. What the P0507 code points to is a high idle with no justified reason, with every accessory off and the engine fully warm.

P0507 code symptoms

• Idle clearly higher than normal, often above 1,000 rpm with the engine warm.
• Check engine light on.
• The vehicle pulls forward with force when you release the brake.
• Less effective braking because of the engine push.
• Higher fuel use in city driving.
• Harsh shifts in automatic transmissions when coming to a stop.
• An audible hiss if there is a large vacuum leak.
• The idle rises only with accessories on, which can be normal behavior and not a fault.

Likely causes of the P0507 code

1. Vacuum leaks in hoses, the intake manifold gasket, the PCV valve or the brake booster. The most frequent cause.
2. Carbon buildup in the throttle body that keeps the throttle plate from closing fully.
3. Adaptations not reset after cleaning or replacing the throttle body.
4. Idle control valve stuck open on the systems that have one.
5. Throttle cable out of adjustment on vehicles with a mechanical linkage.
6. Deteriorated throttle body gasket.
7. Coolant temperature sensor reporting a cold engine, which keeps the warm-up idle active.
8. Canister purge valve that does not close.

How to diagnose the P0507 code step by step

1. Compare commanded and actual idle speed in live data. The difference confirms the code, and its size gives you a hint about the cause.
2. Listen to the engine for hissing from a vacuum leak, which is easiest to hear at idle.
3. Run a smoke test on the intake to pinpoint leaks accurately.
4. Check the temperature the coolant sensor reports. If it says the engine is cold, the computer keeps the warm-up idle on purpose.
5. Inspect the throttle body for carbon that keeps the plate from closing completely.
6. Find out whether the adaptations were reset after any earlier work.
7. Check the PCV valve. One stuck open produces exactly this symptom.
8. Verify the canister purge valve.
9. Check the idle with every accessory off and the engine warm. The rise with the air conditioning or with steering in a turn is normal and does not belong to this code.

How to fix the P0507 code

• Repair the vacuum leaks you located and replace any cracked hoses.
• Replace the PCV valve if it is stuck open.
• Clean the throttle body and reset the adaptations with the scan tool.
• Replace the throttle body gasket if it is deteriorated.
• Clean or replace the idle control valve if it is stuck.
• Correct the coolant temperature sensor if it reports a wrong value.
• Adjust the throttle cable on vehicles with a mechanical linkage.
• Replace the canister purge valve if it does not close.
• Rule out the normal rise caused by accessories before you hunt for leaks. Only a high idle with no justified reason belongs to this code.

After the repair, check with the engine warm that the idle settles at the expected speed and does not climb when you turn on accessories.

Technical reference data

• Normal warm idle: 600 to 850 rpm on most vehicles.
• Warm-up idle: 1,000 to 1,500 rpm, dropping as the engine reaches operating temperature.
• Deviation that sets the code: usually 200 to 300 rpm above the target.
• Throttle opening at warm idle: 2 to 8 percent.
• P0506 is the opposite code: idle lower than expected.
• Resetting the adaptations is mandatory after cleaning the throttle body.
• The computer raises the idle on purpose with the air conditioning, power steering in a turn or the alternator under load.

Brand-specific notes

Before you go looking for leaks, check the temperature the coolant sensor reports. If it says the engine is cold when it is really hot, the computer is keeping the warm-up idle on purpose, and there is no leak to find.

If the P0507 code showed up right after the throttle body was cleaned, the adaptations were almost certainly not reset. It is the most repeated mistake, and it takes two minutes to fix with the scan tool.

Frequently asked questions about P0507