P0507: Idle Control System RPM Higher Than Expected

What Is P0507?

P0507 is a Diagnostic Trouble Code (DTC) defined as “Idle Control System RPM Higher Than Expected.” This code typically activates on cars with electronic throttle control (ETC) — where the accelerator pedal communicates electronically to the throttle instead of using a throttle cable link. It activates when excess or inadequate oxygen enters the engine for combustion, causing poor idling.

In most vehicles, the target idle RPM (revolutions per minute) range is between 600 and 800 RPMs. However, the idle speed can vary depending on the make and model. The way idling is managed also differs between older and newer vehicles. For example:

• In older vehicles, an idle air control (IAC) system helps your car to idle at a predetermined range. Normally, in a stationary car, the throttle plate stays closed. In such a vehicle, the powertrain control module (PCM) uses the idle air control valve as a bypass to allow oxygen into the engine for smooth idling. 

• In newer vehicles, the engine control unit (ECU) works with an electric motor to adjust the throttle plate’s movement, allowing it to control the airflow required for stable idling. 

When your vehicle’s ECU detects that your engine is idling faster than expected, it registers the code P0507 and turns on the check engine light (CEL).   

Error Code P0507 Symptoms

Common signs of the P0507 fault code include: 

• Illuminated check engine light
• Fluctuating or high RPM
• Hard to start the engine
• Rough idling 
• Stalling engine 
• Harsh engagement of the transmission

14 Potential Causes of P0507

Here are some likely triggers for fault code P0507: 

1. Vacuum leak due to cracks in the intake near the throttle body
2. Vacuum leak due to a damaged hose or cracked canister in the EVAP system
3. Clogged or faulty idle air control valve (IAC valve)
4. Failed idle air controller circuit
5. Carbon buildup on the throttle body
6. Malfunctioning throttle position sensor (TPS)
7. Faulty electric throttle control actuator
8. Failing power steering pressure switch
9. Damaged engine coolant temperature (ECT) sensor
10. Bad mass airflow (MAF) sensor
11. A stuck exhaust gas recirculation (EGR valve) and positive crankcase ventilation (PCV valve)
12. Restricted exhaust
13. A charging issue, like a failed alternator
14. Faulty PCM or ECM (engine control module)

Can You Still Drive with an Active P0507 Trouble Code?

Yes, you can continue driving, as a DTC P0507 won’t immediately affect your engine’s health.

But here’s the thing:
If you delay the service for long, you may experience drivability issues, like engine stalling or difficulty starting. Long-term driving with an active DTC P0507 could also lead to increased exhaust emissions and high idle RPM, damaging your engine parts. 

Once your engine is extensively damaged, you’ll need major repairs that might require several new parts and cost a lot of money.

How to Diagnose a P0507 the Right Way

To diagnose the issue, you need in-depth information about throttle bodies in different cars, as the steps may vary between Honda, Chevrolet, Nissan, and other car models. You also need access to materials like a scan tool and a smoke machine. 

So, for an effective fix, get a qualified mechanic to diagnose your high idle control system RPM.

Here’s how they’ll do it:

1. Use an OBD-II scan tool to look for other active engine codes, such as P0505 and P0506. When the idle speed is erratic, a car can activate multiple codes. 

2. Look for leaks and cracks near the EVAP system, intake manifold, and vacuum line using a smoke machine. They’ll also check for a hissing sound that could indicate an air leak.

3. Examine the throttle system parts and idle air control valve for carbon buildup. It can prevent the IAC system from functioning smoothly and activate a trouble code. 

4. Verify if there are any corroded or loose wires around the throttle position, ECT, and MAF sensors. Then, use a multimeter to check the sensors’ voltage range. Their ranges should be between:

• 0.5V to 4.5V for TPS 
• 2V (cold engine) and 0.5V (warm engine) for the ECT sensor
• 1V and 5V for the MAF sensor

If the sensors’ readings aren’t as per the information in your owner’s manual, this may explain the active P0507 trouble code.

4. Check the PCV and the EGR valve to see whether they’re stuck. If they’re malfunctioning, they’ll allow excess oxygen into the intake manifold, which may trigger the P0507 code. 

5. Examine the engine idle speed while testing the idle control system and the power steering pressure switch functions. 

6. Test the charging system, including the battery, alternator, and voltage regulator, if other components are functioning properly. A malfunctioning charging system can starve the throttle control of sufficient power, resulting in poor idling and an activated error code.

Possible Solutions and Repairs Costs for Fixing P0507 Code

Here are some repairs and their cost estimates for fixing the P0507 error code: 

• Power steering pressure sensor replacement: $150 to $300
• Throttle body cleaning: $170 to $300
• EGR and PCV valve cleaning: $170 to $450
• MAF sensor replacement: $250 to $470
• Voltage regulator replacement: $150 to $480
• ECT sensor change: $400 to $500
• Throttle position sensor replacement: $150 to $710
• Electronic throttle body replacement: $520 to $710
• IAC valve replacement: $120 to $1,070
• Alternator replacement: $200 to $1,200
• Air leak repair:
  • Vacuum hose replacement: $12 to $210
  • Intake manifold gaskets replacement: $330 to $620

NOTE: The mechanic may also charge $80 to $110 for an idle relearn procedure, which is performed after a throttle body or IAC valve replacement.

These estimates cover the price of new parts and labor but may change based on your vehicle’s model and location. The mechanic may also need to order parts if they are unavailable at your location, adding to the total cost.

For an accurate estimate of how much money you’ll need for the repair service, consult a reputed mechanic in your area or fill up our online form today with your personal information.