Powertrain, generic · Vehicle speed, idle control and auxiliary inputs
P0510 Closed Throttle Position Switch
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo
Older engines with a mechanical throttle have a separate idle contact on the throttle or the combined throttle position sensor (Bosch Motronic throttle switch, Nissan and Toyota sensors with idle switch). The module uses it to recognise idle – for idle control, fuel cut-off on overrun and idle ignition timing – and as a substitute if the position sensor fails. P0510 flags an implausible switch: closed with the throttle open, or open at idle. Manufacturer thresholds were not found in accessible documents; with electronic throttle the switch no longer exists.
Likely causes
Idle switch or throttle sensor misadjusted
Switch contacts worn, dirty or corroded
Wire or connector open or shorted
Throttle not closing (deposits, sticking cable, stop misadjusted)
Value not relearned after replacement
Symptoms
- Idle too high or fluctuating
- Engine stalls when coasting
- No fuel cut-off on overrun (higher consumption)
Repair estimate
DifficultyMediumDIY possible
Parts and labour€30–300
Time0.5–1.5 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
closed throttle switchthrottle position sensorswitch wiringengine control module
Related codes
References: motor.com, hella.com, law.cornell.edu.