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

P0507 Idle Control System RPM - Higher Than Expected

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

CARB requires the idle speed control to be monitored: petrol engines must flag a fault if the target idle speed is not reached within +200/−100 rpm, diesels within ±30 %. Older engines use a separate idle air control valve that bypasses the closed throttle; with electronic throttle the throttle itself controls idle and no separate valve exists. P0507 means the idle speed stays above target although the control is at its minimum – air bypasses the control or the throttle does not close. GM uses more than 182 rpm filtered (MIL after two trips), Ford petrol +200 rpm, Ford diesel +160 rpm, Subaru +200 rpm for 10 s three times; on the Saab 9-4X three overspeed fuel cut-offs at standstill also set it. False air is the classic cause.

Likely causes

False air (vacuum hose, intake gasket, brake booster)
Crankcase ventilation leaking or wrongly routed
Throttle not closing fully (deposits, ice, stop misadjusted)
Idle valve stuck open
Wrong throttle learned value after cleaning or replacement

Symptoms

  • Idle speed too high
  • Automatic car creeps at standstill
  • Hissing from false air

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–500
Time0.5–2 h

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

What to check first

  1. Check for vacuum leaks
  2. Inspect throttle body
  3. Perform idle relearn

Parts involved

idle controlthrottle bodyidle air control valveengine control module

Related codes

P0505P0506P050BP0171P2112

References: gsi.ext.gm.com, saabwisonline.com, saabwisonline.com, fordservicecontent.com.