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Air intakeSeverity Medium: diagnose soon

P0505Idle Air Control System

What it means

The ECU can't get the idle speed to its target: the idle control (or electronic throttle at idle) doesn't respond as expected.

Symptoms

  • Idle too high, too low or hunting
  • Stalling when coming to a stop

Common causes

  • Dirty throttle body or idle valve
  • Vacuum leak
  • Faulty idle control valve
  • Throttle needing a relearn

What to check first

  1. Clean the throttle body or idle valve
  2. Smoke-test for vacuum leaks
  3. Run the idle relearn
Can I drive with P0505? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0505: questions and answers

What does P0505 mean?

P0505: Idle Air Control System. The ECU can't get the idle speed to its target: the idle control (or electronic throttle at idle) doesn't respond as expected.

What are the symptoms of P0505?

Idle too high, too low or hunting. Stalling when coming to a stop.

What causes P0505?

Dirty throttle body or idle valve. Vacuum leak. Faulty idle control valve. Throttle needing a relearn.

How do you diagnose P0505?

1. Clean the throttle body or idle valve 2. Smoke-test for vacuum leaks 3. Run the idle relearn

Can I drive with P0505?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.