High idle switch

Monitors engine temperature during the high idle warm-up period. The high idle icon appears in your rearview mirror. When the engine is warm enough, the idle returns to normal and the icon in your mirror alerts you. The available high idle switch requires 2500 or 3500 models, the Vortec 6.0L V8 SFI engine or Duramax 6.6L Turbo Diesel engine and the Convenience Package. It is not available with 1500 models.