Live Manual
Engine Error

P0505

Idle Control System Malfunction

Severity
Medium

Symptoms

Engine stalling at idle, high idle, erratic idle surging

Common Causes

  • Dirty or failed Idle Air Control (IAC) valve
  • Vacuum leak in intake manifold
  • Carbon buildup in throttle body
  • Faulty coolant temperature sensor

How to Fix

  1. 1 Clean throttle body and IAC passages
  2. 2 Replace IAC valve
  3. 3 Smoke test to find vacuum leaks
  4. 4 Test ECT sensor
Estimated Repair Cost USD
$50 $350

Cleaning: $50 - $100; IAC Valve replacement: $150 - $350