Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P0519 Idle Air Control System Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0519 means the idle control fails functionally with an electrically sound circuit – the actual idle speed deviates strongly despite fully used control. It is documented only on Subaru (also in the Saab 9-2X, electronic throttle, around 2005): idle at least 1000 rpm above target with the control already at zero for 2 or 5 s sets the code with the warning lamp at once, and a fail-safe cuts fuel to cylinders to stop the engine racing. GM and Ford use P0506/P0507 instead; CARB's mandatory limit is +200/−100 rpm.

Likely causes

False air behind the throttle (intake, gasket, vacuum hose)
Throttle or idle valve stuck open (foreign body, coking)
Throttle actuator motor faulty (follow-on P2101)
Follow-on fault of other codes (sensors, pedal)

Symptoms

  • Idle far above target, engine races
  • Jerking from cylinder cut-off in limp mode
  • Check engine light on

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–450
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

idle controlthrottle bodyengine control module

Related codes

P0505P0506P0507P0511P2101P0171

References: saabwisonline.com, saabwisonline.com, law.cornell.edu, gsi.ext.gm.com.