OBD-II Code · Sensors
P0510
Closed Throttle Position Switch Malfunction
Severity
medium
Worth booking. It costs fuel, emissions or comfort until it is fixed.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$80–$300
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Closed throttle switch not reporting correctly.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
- Stalling at decel
Likely causes
- Failed switch/TPSMost common
- Wiring
Read the full diagnostic procedureP0510 is a legacy code from the cable-throttle era indicating the closed throttle position switch (a discrete on/off switch separate from the TPS pot…
P0510 is a legacy code from the cable-throttle era indicating the closed throttle position switch (a discrete on/off switch separate from the TPS potentiometer) is not transitioning from closed to open as the throttle plate moves off idle, or vice versa. On modern drive-by-wire vehicles this code is essentially obsolete and you will only see it on pre-2005 applications that still used a mechanical idle switch in parallel with the analog TPS.
Cheapest-first
- back-probe the idle switch signal wire with a meter and verify it pulls to ground when the throttle is fully closed and opens (5V or floating) the instant the pedal is touched, then if the switch is mechanical and adjustable, loosen the mounting screws and rotate to spec.
- If the switch is integral to the TPS assembly, the entire TPS gets replaced as a unit.
- Caveat: on vehicles where this is a separate switch, a sticky throttle cable or a misadjusted idle stop screw will hold the throttle plate slightly open at hot idle and set this code without any switch fault at all.
Vehicle-specific patterns1996-2002 Toyota 4Runner, Tacoma, and T100 with the 3.4L 5VZ-FE use a separate idle switch on the throttle body that corrodes internally.
- 1996-2002Toyota 4Runner, Tacoma, and T100 with the 3.4L 5VZ-FE use a separate idle switch on the throttle body that corrodes internally.
- 1995-2001Nissan Pathfinder, Maxima, and Frontier have the closed throttle switch built into the TPS and the whole sensor is replaced when it sticks.
- 1996-2000Honda Accord and Civic with the secondary idle-air-control-adjacent closed-throttle switch fail from carbon buildup holding the throttle plate cracked open.
- 1997-2003Subaru Legacy and Forester see TPS-integrated idle switches fail from contact wear.
Estimated repair$70 to $240.
Look up another code
P0510 — frequently asked
What does a P0510 code mean?
Closed throttle switch not reporting correctly.
What causes a P0510 code?
Common causes: Failed switch/TPS; Wiring.
What are the symptoms of a P0510 code?
Typical symptoms: Check engine light; Stalling at decel.
Is it safe to drive with a P0510 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $80-$300.
How do I diagnose a P0510 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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