P0510 Closed Throttle Position Switch Malfunction

P0510 points to a closed throttle position switch malfunction. The controller is not seeing the expected closed-throttle confirmation when the throttle returns to idle.

Code details

Generic OBD-II · P0

System: Speed / Idle
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not adjust throttle stops blindly; confirm the closed-throttle signal and mechanical return first.

Symptoms of P0510

Unstable, high, or low idle, or stalling.
Erratic speedometer, cruise-control, or shift behaviour.
Check-engine light with a hesitation or surge.

Common causes of P0510

A dirty throttle body, idle-control valve, or throttle-position sensor.
A failing vehicle-speed or wheel-speed sensor, or its wiring.
Vacuum leaks or a related sensor forcing the idle/speed strategy.

Useful checks before replacing parts

Compare closed throttle switch status, throttle position sensor data, accelerator pedal position, idle speed, freeze-frame conditions, and related throttle codes.
Inspect throttle stop position, switch adjustment, wiring, connector condition, carbon buildup, cable or pedal binding, and throttle plate return.
Verify the switch changes state consistently as the throttle just leaves and returns to the closed position.

Related OBD-II codes

These nearby speed / idle entries can help compare wording and pin down the fault area.