P0510 Code Meaning and Next Steps

First checks take 10 to 20 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine stalls repeatedly or will not stay running at idle.
!The vehicle loses power badly enough that it becomes unsafe to continue.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but idle quality should be watched closely.

What to check first

Step-by-step checks

1
Free - no tools
Check whether the throttle cable or pedal returns fully to closed position
2
Free - no tools
Inspect the throttle-body connector and wiring for damage or poor fit
3
Basic tool needed
If the vehicle uses a throttle position or closed-throttle switch, confirm whether it is adjusted correctly
4
Basic tool needed
Notice whether the code appeared after throttle-body cleaning or replacement
5
Basic tool needed
If scan data is available, compare closed-throttle readings with the commanded idle state

If the code returns

-If the switch or signal is wrong only at the stop position, adjustment or connector work may fix it.
-If the code returns after a replacement, confirm the throttle body and harness were installed correctly.
-If idle problems are also present, treat them together because the ECU may not trust closed-throttle status.

Background

What this code means

P0510 is a generic OBD-II idle-control code.

These codes usually mean the ECU is not able to keep idle speed where it wants it, either because the air path is off, the throttle body is dirty, or a related sensor signal is not believable.

Idle may be unstable, throttle response may feel odd, or the ECU may not know when the throttle is fully closed.

Diagnosis

Common causes

Most common

Misadjusted throttle switch

The ECU may never see a true closed-throttle state.

Common

Throttle-body sensor fault

The position signal can be outside the normal range.

Common

Connector or wiring issue

A bad pin fit can interrupt the closed-throttle signal.

Possible

Thottle plate not fully closing

Carbon or linkage issues can keep the throttle slightly open.

Avoid these mistakes

What not to do

xDo not replace the throttle body first if the intake is dirty, leaking, or obviously sticking.
xDo not ignore vacuum leaks, because they can mimic a bad idle-control part.

Parts

Parts that may need replacing

PartTypical costNotes

Throttle position sensor or switch$30-$180Relevant when the closed-throttle signal is wrong.

Throttle body cleaning or service$10-$120Worth checking if the throttle plate is sticking.

Connector pigtail repair$15-$90Relevant if the connector or wiring is damaged.

Related OBD codes

P0505

P0505 usually means the idle control system is not holding normal idle speed.

P0506

P0506 usually means the idle speed is lower than the ECU expects.

P0507

P0507 usually means the idle speed is higher than the ECU expects.

P0120

P0120 usually means the throttle position sensor circuit is not behaving correctly.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0510 was expanded around common closed-throttle signal faults, including throttle switch adjustment, sensor issues, and wiring problems.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0510 - P0510 Usually Means the Closed-throttle Position Switch or Signal Is Not Behaving Correctly