گیر کردن دریچه بای‌پس اینترکولر

The flap routing charge air either through the intercooler or around it, seized. The bypass exists for cold running — cold dense air is wanted when the engine is warm, and warm air helps it reach temperature quickly.

Stuck in bypass, charge air is never cooled, so intake temperatures climb under boost, the module pulls timing to protect the engine, and power falls away on a sustained run. Stuck in the cooled position, warm-up is slowed and condensation forms in a cooler that never gets hot. Check the flap moves freely by hand with the actuator disconnected — a seized flap and a failed actuator give the same performance code and want different repairs, and this one lives in the charge air stream where oil mist collects.