P0507: P0507 Diagnostic Guide

What this code means

P0507 may mean the engine idle speed is higher than the control module expects or commands.

What the vehicle may do

The vehicle may idle higher than normal.
The idle can hang or feel slow to settle.
The driver may notice an elevated idle when stopped.

Possible fault areas

A throttle body condition may be involved.
A PCV system issue can be possible.
A vacuum leak at the engine or intake manifold may be involved.
Extra unmetered air often can affect idle control.

Diagnostic path

Open on what P0507 means

On this 2019 to 2025 Silverado 1500 with the 5.3 gas engine, P0507 is a high idle code. In plain terms, the engine speed may be higher than what the control module is trying to command at idle. The driver may notice a fast idle, a hanging idle, or an idle that feels like it does not settle down cleanly. Broadly, this can come from extra air getting into the engine, a PCV issue, a throttle body that is not closing cleanly, or a vacuum leak around the engine or intake manifold. The diagnostic path is about proving that, not guessing at parts.

Start with the basic checks

Before getting into the P0507 checks, start with the basic system checks, follow a structured diagnostic approach, and make sure you are working from the right diagnostic category for the code and symptom. Put the ignition on with the vehicle in service mode, then make sure there are no other codes set. If other codes are present, check what they mean first, because this idle code should not be diagnosed in isolation when another fault may be driving the idle behavior.

Use the monitor gates before judging the code

For the monitor to be valid, treat the run criteria as gates, not as a parts list. Barometric Pressure has to be Greater than 70 kPa (10 PSI). The Engine has to be Idling for greater than 10 s and Running for greater than 1 min. Engine Coolant Temperature has to be Greater than 60°C (140°F). Engine speed has to vary less than +/-25 RPM. Ignition and Start Signal has to be 11 to 32 V. Intake Air Temperature Sensor has to be Greater than −20°C (−4°F). Vehicle Speed has to be Less than 1.6 km/h (1 MPH). Once those gates are met, the DTC runs continuously for greater than 10 s. Also make sure the related non-numbered gates are not being disturbed, like scan tool controls being inactive and the vehicle not being in a shifting event.

Understand the P0507 trigger

For P0507, the key idea is commanded idle versus actual idle. This code sets when Engine Speed is 188 RPM Greater than desired for greater than 10 s. So the scan data needs to be judged against desired idle, not just by whether the engine sounds a little fast.

Check idle air flow compensation first

With no other codes setting, look at the scan tool parameter for Throttle Body Idle Air Flow Compensation. The expected value is Less than 90%. If that value is 90% or greater, the diagnostic path moves toward throttle body cleaning. If it is less than 90%, keep going with the idle speed verification.

Verify actual idle against desired idle

Now run the engine at idle with the engine at normal operating temperature. Compare Engine Speed to Desired Idle Speed. The expected range is -93 to +187 RPM of the Desired Idle Speed. If the engine speed is outside that range, move into the testing path. If it is in range, reproduce the operating conditions for the code, or the captured conditions from when the fault happened, and confirm P0507 does not reset. If the code cannot run, a no-code result does not prove the fault is gone.

Keep the low-idle branch separate

There is a separate low-idle testing branch that checks for a parasitic engine load, a restricted exhaust, or a mechanical condition where engine speed is limited. That branch is useful context, but do not let it pull you away from this high-idle diagnosis unless the data and code path point there.

P0507 system testing

For this P0507 path, check for the listed high-idle conditions. Make sure the throttle body is not binding or sticking at closed. Check the PCV system for leaks, incorrect connection, or restriction. Also check for a vacuum leak at the engine or intake manifold. If one of those conditions exists, correct that issue. If none of those conditions exist, the path is considered OK at that point.

Verify and close

After any correction, keep verification separate from testing. Verify the repair and confirm the code stays gone under the conditions that allow the monitor to run. The takeaway: P0507 is a high idle diagnosis, so follow the scan data, prove the idle error, then check the throttle body, PCV system, and vacuum leak areas in order. For more diagnostic training, visit stepdiagnostics.com.