P0507: Idle Control System RPM Higher Than Expected

What Is P0507?

P0507 is a Diagnostic Trouble Code defined as “Idle Control System RPM Higher Than Expected.”

The Idle Air Control System is typically part of your vehicle’s electronic throttle body assembly. It comprises the idle air control valve (IAC) that, along with the Powertrain Control Module (PCM), determines the amount of air the engine needs to run at an optimal level. 

When the driver presses the accelerator pedal, the throttle plate rotates within the throttle body, allowing more air to enter the throttle opening, increasing engine speed. However, at idle, the throttle plate is closed, reducing airflow into the engine. 

The idle air control valve bypasses the closed throttle plate, so the engine gets the air it needs for combustion. In this way, the Idle Air Control System ensures that your engine runs at optimal idle speed while the vehicle is not moving. 

Usually, the target idle speed or RPM range falls between 600 to 800 RPMs for most vehicles. However, the idle speed can still vary depending on the make and model. 

When your vehicle’s PCM detects that the engine’s idling at a higher speed than the target idle speed, it sets the P0507 code and activates the Check Engine Light. 

The idle control system code P0507 is usually activated on cars with electronic throttle control — where the accelerator pedal is connected electronically to the throttle instead of a traditional throttle cable. 

Common Symptoms

In the case of the P0507 trouble code, you’ll notice the idle speed on the tachometer is higher than the target engine speed, making this issue pretty easy to spot, even for an inexperienced vehicle owner. 

Some of the common symptoms of P0507 code include: 

• An illuminated Check Engine Light
• Fluctuating or high idle speed
• Hard to start the engine
• Rough idling 
• Stalling engine 
• Harsh engagement of the transmission

Can I Still Drive?

You can continue to drive with the P0507 code for a short duration, as it won’t immediately affect your engine’s health. 

However, you may experience some drivability issues with code P0507, like engine stalling or difficulty starting, but your engine won’t die. 

That said, you should ideally get the P0507 trouble code fixed soon. Long-term driving with an active DTC P0507 could lead to excessive fuel consumption. The high idle speed can also damage your engine components.

P0507 Causes

One of the most common reasons that set off the  DTC P0507 is not a faulty idle control system but an engine vacuum leak. 

A vacuum leak can trigger the P0507 trouble code and activate the Check Engine Light even if the idle air control valve is closed. 

Here are some of the other probable causes for code P0507: 

• Faulty or clogged Idle Air Control valve (idle air valve or IAC valve)
• Problems with the throttle body or electronic throttle control
• Restricted exhaust
• Failed IAC (Idle Air Controller) circuit  
• Faulty electric throttle control actuator
• Engine mechanical problems
• An issue with the idle control system
• Sensor problems
• A charging issue like a failed alternator 
• Carbon build-up on the throttle body
• Faulty power steering pressure switch
• A leak in the EGR valve
• Faulty positive crankcase ventilation valve (PCV valve)

Diagnosis

Whether you own a Honda Motor Company vehicle or a Hyundai car, several reasons could cause your PCM to register the code P0507 (high idle control system RPM) and activate the check engine light. 

Here’s how a mechanic will diagnose the root cause of DTC P0507:

1. Check for Other Trouble Codes
Use an OBD-II scanner to check if your vehicle has registered any other diagnostic trouble code. If any other trouble code is present, they’ll address it first. 

2. Take a Test Drive
After clearing the trouble code, they’ll take a test drive of your vehicle to see if the Check Engine Light turns on and if the P0507 code returns.

3. Check for a Vacuum Leak
If the P0507 code issue persists, they’ll visually inspect the intake and vacuum hoses for any disconnection or vacuum leak. They’ll also check for a hissing sound that could indicate an intake leak.

4. Examine the Throttle Body and Idle Air Valve
Inspect the throttle body along with the throttle plate, throttle valve, and idle air control valve for any carbon build-up. They’ll use a carb cleaner or a specific throttle body cleaner to wipe off the deposits.

5. Check if the Cable Is Too Tight
If your vehicle has a cable-operated throttle body, they’ll ensure that the cable isn’t too tight, causing the throttle valve to be open at idle.

6. Inspect the PCV Valve
Check the PCV valve and clean it with a carb cleaner if it’s clogged or blocked.

7. Examine the Engine Idle Speed
Check the engine RPM (engine idle speed) while testing the idle control system and the power steering pressure switch functions. Some vehicles may employ an idle relearn procedure to repair the idle speed surge.

8. Examine the Charging System
Test the charging system, including the battery, the alternator, and the voltage regulator.

Possible Repairs for P0507 & Costs

Anything from an intake vacuum leak to a faulty electric throttle control actuator issue can activate the DTC P0507. So, a proper diagnosis by a certified technician is essential. 

Fixing the P0507 code usually begins with an hour of diagnostic time that could cost you $75-$150. Based on that, the mechanic will give you an estimate of the required repair or part replacement. 

Here are some of the possible repair and replacement cost estimates for P0507 code: 

• Adjust throttle cable: $50 to $125
• Clean throttle body: $75 to $200
• Relearn idle air volume: $75 to $250
• Repair a vacuum leak: $150 to $300
• Clean the idle air control valve: $175 to $400
• Replace power steering pressure sensor: $175 to $350
• Replace idle air control valve (IAC Valve): $125 to $650
• Replace electronic throttle body: $600 to $1200

Note: The average cost estimates mentioned above are inclusive of labor charges.